Summary: Protein kinase C terminal domain
Pfam includes annotations and additional family information from a range of different sources. These sources can be accessed via the tabs below.
This is the Wikipedia entry entitled "Protein kinase C". More...
The Wikipedia text that you see displayed here is a download from Wikipedia. This means that the information we display is a copy of the information from the Wikipedia database. The button next to the article title ("Edit Wikipedia article") takes you to the edit page for the article directly within Wikipedia. You should be aware you are not editing our local copy of this information. Any changes that you make to the Wikipedia article will not be displayed here until we next download the article from Wikipedia. We currently download new content on a nightly basis.
Does Pfam agree with the content of the Wikipedia entry ?
Pfam has chosen to link families to Wikipedia articles. In some case we have created or edited these articles but in many other cases we have not made any direct contribution to the content of the article. The Wikipedia community does monitor edits to try to ensure that (a) the quality of article annotation increases, and (b) vandalism is very quickly dealt with. However, we would like to emphasise that Pfam does not curate the Wikipedia entries and we cannot guarantee the accuracy of the information on the Wikipedia page.
Editing Wikipedia articles
Before you edit for the first time
Wikipedia is a free, online encyclopedia. Although anyone can edit or contribute to an article, Wikipedia has some strong editing guidelines and policies, which promote the Wikipedia standard of style and etiquette. Your edits and contributions are more likely to be accepted (and remain) if they are in accordance with this policy.
You should take a few minutes to view the following pages:
How your contribution will be recorded
Anyone can edit a Wikipedia entry. You can do this either as a new user or you can register with Wikipedia and log on. When you click on the "Edit Wikipedia article" button, your browser will direct you to the edit page for this entry in Wikipedia. If you are a registered user and currently logged in, your changes will be recorded under your Wikipedia user name. However, if you are not a registered user or are not logged on, your changes will be logged under your computer's IP address. This has two main implications. Firstly, as a registered Wikipedia user your edits are more likely seen as valuable contribution (although all edits are open to community scrutiny regardless). Secondly, if you edit under an IP address you may be sharing this IP address with other users. If your IP address has previously been blocked (due to being flagged as a source of 'vandalism') your edits will also be blocked. You can find more information on this and creating a user account at Wikipedia.
If you have problems editing a particular page, contact us at email@example.com and we will try to help.
The community annotation is a new facility of the Pfam web site. If you have problems editing or experience problems with these pages please contact us.
Protein kinase C Edit Wikipedia article
|Protein kinase C|
|PDB structures||RCSB PDB PDBe PDBsum|
|Gene Ontology||AmiGO / EGO|
|Protein kinase C terminal domain|
Protein kinase C also known as PKC (EC 22.214.171.124) is a family of protein kinase enzymes that are involved in controlling the function of other proteins through the phosphorylation of hydroxyl groups of serine and threonine amino acid residues on these proteins. PKC enzymes in turn are activated by signals such as increases in the concentration of diacylglycerol (DAG) or calcium ions (Ca2+). Hence PKC enzymes play important roles in several signal transduction cascades.
The PKC family consists of fifteen isozymes in humans. They are divided into three subfamilies, based on their second messenger requirements: conventional (or classical), novel, and atypical. Conventional (c)PKCs contain the isoforms α, βI, βII, and γ. These require Ca2+, DAG, and a phospholipid such as phosphatidylserine for activation. Novel (n)PKCs include the δ, ε, η, and θ isoforms, and require DAG, but do not require Ca2+ for activation. Thus, conventional and novel PKCs are activated through the same signal transduction pathway as phospholipase C. On the other hand, atypical (a)PKCs (including protein kinase Mζ and ι / λ isoforms) require neither Ca2+ nor diacylglycerol for activation. The term "protein kinase C" usually refers to the entire family of isoforms.
- conventional - require DAG, Ca2+, and phospholipid for activation
- novel - require DAG but not Ca2+ for activation
- atypical - require neither Ca2+ nor DAG for activation (require phosphatidyl serine)
- related PKD
- related PKN
The structure of all PKCs consists of a regulatory domain and a catalytic domain tethered together by a hinge region. The catalytic region is highly conserved among the different isoforms, as well as, to a lesser degree, among the catalytic region of other serine/threonine kinases. The second messenger requirement differences in the isoforms are a result of the regulatory region, which are similar within the classes, but differ among them. Most of the crystal structure of the catalytic region of PKC has not been determined, except for PKC theta and iota. Due to its similarity to other kinases whose crystal structure have been determined, the structure can be strongly predicted.
The regulatory domain or the amino-teminus of the PKCs contains several shared subregions. The C1 domain, present in all of the isoforms of PKC has a binding site for DAG as well as non-hydrolysable, non-physiological analogues called phorbol esters. This domain is functional and capable of binding DAG in both conventional and novel isoforms, however, the C1 domain in atypical PKCs is incapable of binding to DAG or phorbol esters. The C2 domain acts as a Ca2+ sensor and is present in both conventional and novel isoforms, but functional as a Ca2+ sensor only in the conventional. The pseudosubstrate region, which is present in all three classes of PKC, is a small sequence of amino acids that mimic a substrate and bind the substrate-binding cavity in the catalytic domain,lack critical serine, threonine phosphoacceptor residues, keeping the enzyme inactive. When Ca2+ and DAG are present in sufficient concentrations, they bind to the C2 and C1 domain, respectively, and recruit PKC to the membrane. This interaction with the membrane results in release of the pseudosubstrate from the catalytic site and activation of the enzyme. In order for these allosteric interactions to occur, however, PKC must first be properly folded and in the correct conformation permissive for catalytic action. This is contingent upon phosphorylation of the catalytic region, discussed below.
The catalytic region or kinase core of the PKC allows for different functions to be processed; PKB (also known as Akt) and PKC kinases contains approximately 40% amino acid sequence similarity. This similarity increases to ~ 70% across PKCs and even higher when comparing within classes. For example, the two atypical PKC isoforms, ζ and ι/λ, are 84% identical (Selbie et al., 1993). Of the over-30 protein kinase structures whose crystal structure has been revealed, all have the same basic organization. They are a bilobal structure with a β sheet comprising the N-terminal lobe and an α helix constituting the C-terminal lobe. Both the ATP- and substrate-binding sites are located in the cleft formed by these two lobes. This is also where the pseudosubstrate domain of the regulatory region binds.[context needed]
Another feature of the PKC catalytic region that is essential to the viability of the kinase is its phosphorylation. The conventional and novel PKCs have three phosphorylation sites, termed: the activation loop, the turn motif, and the hydrophobic motif. The atypical PKCs are phosphorylated only on the activation loop and the turn motif. Phosphorylation of the hydrophobic motif is rendered unnecessary by the presence of a glutamic acid in place of a serine, which, as a negative charge, acts similar in manner to a phosphorylated residue. These phosphorylation events are essential for the activity of the enzyme, and 3-phosphoinositide-dependent protein kinase-1 (PDK1) is the upstream kinase responsible for initiating the process by transphosphorylation of the activation loop.
The consensus sequence of protein kinase C enzymes is similar to that of protein kinase A, since it contains basic amino acids close to the Ser/Thr to be phosphorylated. Their substrates are, e.g., MARCKS proteins, MAP kinase, transcription factor inhibitor IκB, the vitamin D3 receptor VDR, Raf kinase, calpain, and the epidermal growth factor receptor.
Upon activation, protein kinase C enzymes are translocated to the plasma membrane by RACK proteins (membrane-bound receptor for activated protein kinase C proteins). The protein kinase C enzymes are known for their long-term activation: They remain activated after the original activation signal or the Ca2+-wave is gone. It is presumed that this is achieved by the production of diacylglycerol from phosphatidylinositol by a phospholipase; fatty acids may also play a role in long-term activation.
A multiplicity of functions have been ascribed to PKC. Recurring themes are that PKC is involved in receptor desensitization, in modulating membrane structure events, in regulating transcription, in mediating immune responses, in regulating cell growth, and in learning and memory. These functions are achieved by PKC-mediated phosphorylation of other proteins. However, the substrate proteins present for phosphorylation vary, since protein expression is different between different kinds of cells. Thus, effects of PKC are cell-type-specific:
Protein kinase C, activated by tumor promoter phorbol ester, may phosphorylate potent activators of transcription, and thus lead to increased expression of oncogenes, promoting cancer progression, or interfere with other phenomena.
Protein kinase C inhibitors, such as ruboxistaurin, may potentially be beneficial in peripheral diabetic nephropathy. The Protein kinase C activator ingenol mebutate, derived from the plant Euphorbia peplus, is FDA-approved for the treatment of actinic keratosis.
- Wilson CH, Ali ES, Scrimgeour N, Martin AM, Hua J, Tallis GA, Rychkov GY, Barritt GJ (2015). "Steatosis inhibits liver cell store-operated Ca²⁺ entry and reduces ER Ca²⁺ through a protein kinase C-dependent mechanism". The Biochemical Journal 466 (2): 379–90. doi:10.1042/BJ20140881. PMID 25422863.
- Mellor H, Parker PJ (Jun 1998). "The extended protein kinase C superfamily". The Biochemical Journal. 332 332 (Pt 2): 281–92. doi:10.1042/bj3320281. PMC 1219479. PMID 9601053.
- Nishizuka Y (Apr 1995). "Protein kinase C and lipid signaling for sustained cellular responses" (abstract). FASEB Journal 9 (7): 484–96. PMID 7737456.
- Balendran A, Biondi RM, Cheung PC, Casamayor A, Deak M, Alessi DR (Jul 2000). "A 3-phosphoinositide-dependent protein kinase-1 (PDK1) docking site is required for the phosphorylation of protein kinase Czeta (PKCzeta ) and PKC-related kinase 2 by PDK1". The Journal of Biological Chemistry 275 (27): 20806–13. doi:10.1074/jbc.M000421200. PMID 10764742.
- Biancani P, Harnett KM (2006). "Signal transduction in lower esophageal sphincter circular muscle, PART 1: Oral cavity, pharynx and esophagus". GI Motility online. doi:10.1038/gimo24.
- Fitzpatrick, David; Purves, Dale; Augustine, George (2004). "Table 20:2". Neuroscience (Third ed.). Sunderland, Mass: Sinauer. ISBN 0-87893-725-0.
- Chou EC, Capello SA, Levin RM, Longhurst PA (Dec 2003). "Excitatory alpha1-adrenergic receptors predominate over inhibitory beta-receptors in rabbit dorsal detrusor". The Journal of Urology 170 (6 Pt 1): 2503–7. doi:10.1097/01.ju.0000094184.97133.69. PMID 14634460.
- Rang HP, Dale MM, Ritter JM, Moore PK (2003). "Ch. 10". Pharmacology (5th ed.). Elsevier Churchill Livingstone. ISBN 0-443-07145-4.
- Sanders KM (Jul 1998). "G protein-coupled receptors in gastrointestinal physiology. IV. Neural regulation of gastrointestinal smooth muscle". The American Journal of Physiology 275 (1 Pt 1): G1–7. PMID 9655677.
- Keith Parker; Laurence Brunton; Goodman, Louis Sanford; Lazo, John S.; Gilman, Alfred (2006). Goodman & Gilman's the pharmacological basis of therapeutics (11th ed.). New York: McGraw-Hill. p. 185. ISBN 0-07-142280-3.
- "Entrez Gene: CHRM1 cholinergic receptor, muscarinic 1".
- Walter F., PhD. Boron (2005). Medical Physiology: A Cellular And Molecular Approaoch. Elsevier/Saunders. ISBN 1-4160-2328-3. Page 787
- Yamasaki T, Takahashi A, Pan J, Yamaguchi N, Yokoyama KK (Mar 2009). "Phosphorylation of Activation Transcription Factor-2 at Serine 121 by Protein Kinase C Controls c-Jun-mediated Activation of Transcription". The Journal of Biological Chemistry 284 (13): 8567–81. doi:10.1074/jbc.M808719200. PMC 2659215. PMID 19176525.
- Anderson PW, McGill JB, Tuttle KR (Sep 2007). "Protein kinase C beta inhibition: the promise for treatment of diabetic nephropathy". Current Opinion in Nephrology and Hypertension 16 (5): 397–402. doi:10.1097/MNH.0b013e3281ead025. PMID 17693752.
- Siller G, Gebauer K, Welburn P, Katsamas J, Ogbourne SM (Feb 2009). "PEP005 (ingenol mebutate) gel, a novel agent for the treatment of actinic keratosis: results of a randomized, double-blind, vehicle-controlled, multicentre, phase IIa study". The Australasian Journal of Dermatology 50 (1): 16–22. doi:10.1111/j.1440-0960.2008.00497.x. PMID 19178487.
- "FDA Approves Picato® (ingenol mebutate) Gel, the First and Only Topical Actinic Keratosis (AK) Therapy With 2 or 3 Consecutive Days of Once-Daily Dosing". eMedicine. Yahoo! Finance. January 25, 2012. Retrieved 2012-02-14.
|Wikimedia Commons has media related to
- protein kinase c at the US National Library of Medicine Medical Subject Headings (MeSH)
- Eukaryotic Linear Motif resource motif class MOD_LATS_1
This tab holds the annotation information that is stored in the Pfam database. As we move to using Wikipedia as our main source of annotation, the contents of this tab will be gradually replaced by the Wikipedia tab.
Protein kinase C terminal domain Provide feedback
No Pfam abstract.
External database links
This tab holds annotation information from the InterPro database.
InterPro entry IPR017892
Protein phosphorylation, which plays a key role in most cellular activities, is a reversible process mediated by protein kinases and phosphoprotein phosphatases. Protein kinases catalyse the transfer of the gamma phosphate from nucleotide triphosphates (often ATP) to one or more amino acid residues in a protein substrate side chain, resulting in a conformational change affecting protein function. Phosphoprotein phosphatases catalyse the reverse process. Protein kinases fall into three broad classes, characterised with respect to substrate specificity [PUBMED:3291115]:
- Serine/threonine-protein kinases
- Tyrosine-protein kinases
- Dual specificity protein kinases (e.g. MEK - phosphorylates both Thr and Tyr on target proteins)
Protein kinase function is evolutionarily conserved from Escherichia coli to human [PUBMED:12471243]. Protein kinases play a role in a multitude of cellular processes, including division, proliferation, apoptosis, and differentiation [PUBMED:12368087]. Phosphorylation usually results in a functional change of the target protein by changing enzyme activity, cellular location, or association with other proteins. The catalytic subunits of protein kinases are highly conserved, and several structures have been solved [PUBMED:15078142], leading to large screens to develop kinase-specific inhibitors for the treatments of a number of diseases [PUBMED:15320712].This domain is found in a large variety of protein kinases with different functions and dependencies. Protein kinase C, for example, is a calcium-activated, phospholipid-dependent serine- and threonine-specific enzyme. It is activated by diacylglycerol which, in turn, phosphorylates a range of cellular proteins. This domain is most often found associated with INTERPRO.
The mapping between Pfam and Gene Ontology is provided by InterPro. If you use this data please cite InterPro.
|Molecular function||ATP binding (GO:0005524)|
|protein serine/threonine kinase activity (GO:0004674)|
|Biological process||protein phosphorylation (GO:0006468)|
Below is a listing of the unique domain organisations or architectures in which this domain is found. More...
The graphic that is shown by default represents the longest sequence with a given architecture. Each row contains the following information:
- the number of sequences which exhibit this architecture
a textual description of the architecture, e.g. Gla, EGF x 2, Trypsin.
This example describes an architecture with one
Gladomain, followed by two consecutive
EGFdomains, and finally a single
- a link to the page in the Pfam site showing information about the sequence that the graphic describes
- the UniProt description of the protein sequence
- the number of residues in the sequence
- the Pfam graphic itself.
Note that you can see the family page for a particular domain by clicking on the graphic. You can also choose to see all sequences which have a given architecture by clicking on the Show link in each row.
Finally, because some families can be found in a very large number of architectures, we load only the first fifty architectures by default. If you want to see more architectures, click the button at the bottom of the page to load the next set.
Loading domain graphics...
We store a range of different sequence alignments for families. As well as the seed alignment from which the family is built, we provide the full alignment, generated by searching the sequence database (reference proteomes) using the family HMM. We also generate alignments using four representative proteomes (RP) sets, the UniProtKB sequence database, the NCBI sequence database, and our metagenomics sequence database. More...
There are various ways to view or download the sequence alignments that we store. We provide several sequence viewers and a plain-text Stockholm-format file for download.
We make a range of alignments for each Pfam-A family:
- the curated alignment from which the HMM for the family is built
- the alignment generated by searching the sequence database using the HMM
- Representative Proteomes (RPs) at 15%, 35%, 55% and 75% co-membership thresholds
- alignment generated by searching the UniProtKB sequence database using the family HMM
- alignment generated by searching the NCBI sequence database using the family HMM
- alignment generated by searching the metagenomics sequence database using the family HMM
You can see the alignments as HTML or in three different sequence viewers:
- a Java applet developed at the University of Dundee. You will need Java installed before running jalview
- an HTML page showing the whole alignment.Please note: full Pfam alignments can be very large. These HTML views are extremely large and often cause problems for browsers. Please use either jalview or the Pfam viewer if you have trouble viewing the HTML version
- an HTML-based representation of the alignment, coloured according to the posterior-probability (PP) values from the HMM. As for the standard HTML view, heatmap alignments can also be very large and slow to render.
You can download (or view in your browser) a text representation of a Pfam alignment in various formats:
You can also change the order in which sequences are listed in the alignment, change how insertions are represented, alter the characters that are used to represent gaps in sequences and, finally, choose whether to download the alignment or to view it in your browser directly.
You may find that large alignments cause problems for the viewers and the reformatting tool, so we also provide all alignments in Stockholm format. You can download either the plain text alignment, or a gzipped version of it.
We make a range of alignments for each Pfam-A family. You can see a description of each above. You can view these alignments in various ways but please note that some types of alignment are never generated while others may not be available for all families, most commonly because the alignments are too large to handle.
1Cannot generate PP/Heatmap alignments for seeds; no PP data available
Key: available, not generated, — not available.
Format an alignment
We make all of our alignments available in Stockholm format. You can download them here as raw, plain text files or as gzip-compressed files.
You can also download a FASTA format file containing the full-length sequences for all sequences in the full alignment.
HMM logos is one way of visualising profile HMMs. Logos provide a quick overview of the properties of an HMM in a graphical form. You can see a more detailed description of HMM logos and find out how you can interpret them here. More...
If you find these logos useful in your own work, please consider citing the following article:
This page displays the phylogenetic tree for this family's seed alignment. We use FastTree to calculate neighbour join trees with a local bootstrap based on 100 resamples (shown next to the tree nodes). FastTree calculates approximately-maximum-likelihood phylogenetic trees from our seed alignment.
Note: You can also download the data file for the tree.
Curation and family details
This section shows the detailed information about the Pfam family. You can see the definitions of many of the terms in this section in the glossary and a fuller explanation of the scoring system that we use in the scores section of the help pages.
|Seed source:||Pfam-B_135 (release 1.0)|
|Number in seed:||515|
|Number in full:||3860|
|Average length of the domain:||43.50 aa|
|Average identity of full alignment:||32 %|
|Average coverage of the sequence by the domain:||6.40 %|
|HMM build commands:||
build method: hmmbuild -o /dev/null HMM SEED
search method: hmmsearch -Z 11927849 -E 1000 --cpu 4 HMM pfamseq
|Family (HMM) version:||21|
|Download:||download the raw HMM for this family|
Weight segments by...
Change the size of the sunburst
selected sequences to HMM
a FASTA-format file
- 0 sequences
- 0 species
This visualisation provides a simple graphical representation of the distribution of this family across species. You can find the original interactive tree in the More....
This chart is a modified "sunburst" visualisation of the species tree for this family. It shows each node in the tree as a separate arc, arranged radially with the superkingdoms at the centre and the species arrayed around the outermost ring.
How the sunburst is generated
The tree is built by considering the taxonomic lineage of each sequence that has a match to this family. For each node in the resulting tree, we draw an arc in the sunburst. The radius of the arc, its distance from the root node at the centre of the sunburst, shows the taxonomic level ("superkingdom", "kingdom", etc). The length of the arc represents either the number of sequences represented at a given level, or the number of species that are found beneath the node in the tree. The weighting scheme can be changed using the sunburst controls.
In order to reduce the complexity of the representation, we reduce the number of taxonomic levels that we show. We consider only the following eight major taxonomic levels:
Colouring and labels
Segments of the tree are coloured approximately according to their superkingdom. For example, archeal branches are coloured with shades of orange, eukaryotes in shades of purple, etc. The colour assignments are shown under the sunburst controls. Where space allows, the name of the taxonomic level will be written on the arc itself.
As you move your mouse across the sunburst, the current node will be highlighted. In the top section of the controls panel we show a summary of the lineage of the currently highlighed node. If you pause over an arc, a tooltip will be shown, giving the name of the taxonomic level in the title and a summary of the number of sequences and species below that node in the tree.
Anomalies in the taxonomy tree
There are some situations that the sunburst tree cannot easily handle and for which we have work-arounds in place.
Missing taxonomic levels
Some species in the taxonomic tree may not have one or more of the main eight levels that we display. For example, Bos taurus is not assigned an order in the NCBI taxonomic tree. In such cases we mark the omitted level with, for example, "No order", in both the tooltip and the lineage summary.
Unmapped species names
The tree is built by looking at each sequence in the full alignment for the family. We take the name of the species given by UniProt and try to map that to the full taxonomic tree from NCBI. In some cases, the name chosen by UniProt does not map to any node in the NCBI tree, perhaps because the chosen name is listed as a synonym or a misspelling in the NCBI taxonomy.
So that these nodes are not simply omitted from the sunburst tree, we group them together in a separate branch (or segment of the sunburst tree). Since we cannot determine the lineage for these unmapped species, we show all levels between the superkingdom and the species as "uncategorised".
Since we reduce the species tree to only the eight main taxonomic levels, sequences that are mapped to the sub-species level in the tree would not normally be shown. Rather than leave out these species, we map them instead to their parent species. So, for example, for sequences belonging to one of the Vibrio cholerae sub-species in the NCBI taxonomy, we show them instead as belonging to the species Vibrio cholerae.
Too many species/sequences
For large species trees, you may see blank regions in the outer layers of the sunburst. These occur when there are large numbers of arcs to be drawn in a small space. If an arc is less than approximately one pixel wide, it will not be drawn and the space will be left blank. You may still be able to get some information about the species in that region by moving your mouse across the area, but since each arc will be very small, it will be difficult to accurately locate a particular species.
The tree shows the occurrence of this domain across different species. More...
We show the species tree in one of two ways. For smaller trees we try to show an interactive representation, which allows you to select specific nodes in the tree and view them as an alignment or as a set of Pfam domain graphics.
Unfortunately we have found that there are problems viewing the interactive tree when the it becomes larger than a certain limit. Furthermore, we have found that Internet Explorer can become unresponsive when viewing some trees, regardless of their size. We therefore show a text representation of the species tree when the size is above a certain limit or if you are using Internet Explorer to view the site.
If you are using IE you can still load the interactive tree by clicking the "Generate interactive tree" button, but please be aware of the potential problems that the interactive species tree can cause.
For all of the domain matches in a full alignment, we count the number that are found on all sequences in the alignment. This total is shown in the purple box.
We also count the number of unique sequences on which each domain is found, which is shown in green. Note that a domain may appear multiple times on the same sequence, leading to the difference between these two numbers.
Finally, we group sequences from the same organism according to the NCBI code that is assigned by UniProt, allowing us to count the number of distinct sequences on which the domain is found. This value is shown in the pink boxes.
We use the NCBI species tree to group organisms according to their taxonomy and this forms the structure of the displayed tree. Note that in some cases the trees are too large (have too many nodes) to allow us to build an interactive tree, but in most cases you can still view the tree in a plain text, non-interactive representation. Those species which are represented in the seed alignment for this domain are highlighted.
You can use the tree controls to manipulate how the interactive tree is displayed:
- show/hide the summary boxes
- highlight species that are represented in the seed alignment
- expand/collapse the tree or expand it to a given depth
- select a sub-tree or a set of species within the tree and view them graphically or as an alignment
- save a plain text representation of the tree
Please note: for large trees this can take some time. While the tree is loading, you can safely switch away from this tab but if you browse away from the family page entirely, the tree will not be loaded.
There are 4 interactions for this family. More...
We determine these interactions using iPfam, which considers the interactions between residues in three-dimensional protein structures and maps those interactions back to Pfam families. You can find more information about the iPfam algorithm in the journal article that accompanies the website.
For those sequences which have a structure in the Protein DataBank, we use the mapping between UniProt, PDB and Pfam coordinate systems from the PDBe group, to allow us to map Pfam domains onto UniProt sequences and three-dimensional protein structures. The table below shows the structures on which the Pkinase_C domain has been found. There are 83 instances of this domain found in the PDB. Note that there may be multiple copies of the domain in a single PDB structure, since many structures contain multiple copies of the same protein seqence.
Loading structure mapping...