Summary: Peptidase inhibitor I9
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This is the Wikipedia entry entitled "Protease inhibitor (biology)". More...
Protease inhibitor (biology) Edit Wikipedia article
In biology and biochemistry, protease inhibitors, or antiproteases,[1] are molecules that inhibit the function of proteases (enzymes that aid the breakdown of proteins). Many naturally occurring protease inhibitors are proteins.
In medicine, protease inhibitor is often used interchangeably with alpha 1-antitrypsin (A1AT, which is abbreviated PI for this reason).[2] A1AT is indeed the protease inhibitor most often involved in disease, namely in alpha-1 antitrypsin deficiency.
Classification
Protease inhibitors may be classified either by the type of protease they inhibit, or by their mechanism of action. In 2004 Rawlings and colleagues introduced a classification of protease inhibitors based on similarities detectable at the level of amino acid sequence.[3] This classification initially identified 48 families of inhibitors that could be grouped into 26 related superfamily (or clans) by their structure. According to the MEROPS database there are now 81 families of inhibitors. These families are named with an I followed by a number, for example, I14 contains hirudin-like inhibitors.
By protease
Classes of proteases are:
- Aspartic protease inhibitors
- Cysteine protease inhibitors
- Metalloprotease inhibitors
- Serine protease inhibitors
- Threonine protease inhibitors
- Trypsin inhibitors
By mechanism
Classes of inhibitor mechanisms of action are:
- Suicide inhibitor
- Transition state inhibitor
- Protein protease inhibitor (see serpins)
- Chelating agents
Families
Inhibitor I4
This is a family of protease suicide inhibitors called the serpins. It contains inhibitors of multiple cysteine and serine protease families. Their mechanism of action relies on undergoing a large conformational change which inactivates their target's catalytic triad.
Inhibitor I9
| Peptidase inhibitor I9 | |||||||||
|---|---|---|---|---|---|---|---|---|---|
 subtilisin bpn' prosegment (77 residues) complexed with a mutant subtilisin bpn' (266 residues). crystal ph 4.6. crystallization temperature 20 c diffraction temperature-160 c | |||||||||
| Identifiers | |||||||||
| Symbol | Inhibitor_I9 | ||||||||
| Pfam | PF05922 | ||||||||
| InterPro | IPR010259 | ||||||||
| MEROPS | I9 | ||||||||
| SCOPe | 1gns / SUPFAM | ||||||||
| |||||||||
Proteinase propeptide inhibitors (sometimes referred to as activation peptides) are responsible for the modulation of folding and activity of the peptidase pro-enzyme or zymogen. The pro-segment docks into the enzyme, shielding the substrate binding site, thereby promoting inhibition of the enzyme. Several such propeptides share a similar topology, despite often low sequence identities.[4][5] The propeptide region has an open-sandwich antiparallel-alpha/antiparallel-beta fold, with two alpha-helices and four beta-strands with a (beta/alpha/beta)x2 topology. The peptidase inhibitor I9 family contains the propeptide domain at the N-terminus of peptidases belonging to MEROPS family S8A, subtilisins. The propeptide is removed by proteolytic cleavage; removal activating the enzyme.
Inhibitor I10
| Serine endopeptidase inhibitors | |||||||||
|---|---|---|---|---|---|---|---|---|---|
 solution structure of marinostatin, a protease inhibitor, containing two ester linkages | |||||||||
| Identifiers | |||||||||
| Symbol | Inhibitor_I10 | ||||||||
| Pfam | PF12559 | ||||||||
| InterPro | IPR022217 | ||||||||
| |||||||||
This family includes both microviridins and marinostatins. It seems likely that in both cases it is the C-terminus which becomes the active inhibitor after post-translational modifications of the full length, pre-peptide. It is the ester linkages within the key, 12-residue region that circularise the molecule giving it its inhibitory conformation.
Inhibitor I24
| PinA peptidase inhibitor | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| Identifiers | |||||||||
| Symbol | Inhibitor_I24 | ||||||||
| Pfam | PF10465 | ||||||||
| InterPro | IPR019506 | ||||||||
| MEROPS | I24 | ||||||||
| |||||||||
This family includes PinA, which inhibits the endopeptidase La. It binds to the La homotetramer but does not interfere with the ATP binding site or the active site of La.
Inhibitor I29
| Cathepsin propeptide inhibitor domain (I29) | |||||||||
|---|---|---|---|---|---|---|---|---|---|
 crystal structure of a cysteine protease proform | |||||||||
| Identifiers | |||||||||
| Symbol | Inhibitor_I29 | ||||||||
| Pfam | PF08246 | ||||||||
| InterPro | IPR013201 | ||||||||
| |||||||||
The inhibitor I29 domain, which belongs to MEROPS peptidase inhibitor family I29, is found at the N-terminus of a variety of peptidase precursors that belong to MEROPS peptidase subfamily C1A; these include cathepsin L, papain, and procaricain.[6] It forms an alpha-helical domain that runs through the substrate-binding site, preventing access. Removal of this region by proteolytic cleavage results in activation of the enzyme. This domain is also found, in one or more copies, in a variety of cysteine peptidase inhibitors such as salarin.[7]
Inhibitor I34
| Saccharopepsin inhibitor I34 | |||||||||
|---|---|---|---|---|---|---|---|---|---|
 the structure of proteinase a complexed with an ia3 mutant inhibitor | |||||||||
| Identifiers | |||||||||
| Symbol | Inhibitor_I34 | ||||||||
| Pfam | PF10466 | ||||||||
| InterPro | IPR019507 | ||||||||
| MEROPS | I34 | ||||||||
| |||||||||
The saccharopepsin inhibitor I34 is highly specific for the aspartic peptidase saccharopepsin. In the absence of saccharopepsin it is largely unstructured,[8] but in its presence, the inhibitor undergoes a conformational change forming an almost perfect alpha-helix from Asn2 to Met32 in the active site cleft of the peptidase.
Inhibitor I36
| Peptidase inhibitor family I36 | |||||||||
|---|---|---|---|---|---|---|---|---|---|
 the 3d structure of the streptomyces metalloproteinase inhibitor, smpi, isolated from streptomyces nigrescens tk-23, nmr, minimized average structure | |||||||||
| Identifiers | |||||||||
| Symbol | Inhibitor_I36 | ||||||||
| Pfam | PF03995 | ||||||||
| Pfam clan | CL0333 | ||||||||
| InterPro | IPR007141 | ||||||||
| MEROPS | I36 | ||||||||
| SCOPe | 1bhu / SUPFAM | ||||||||
| |||||||||
The peptidase inhibitor family I36 domain is only found in a small number of proteins restricted to Streptomyces species. All have four conserved cysteines that probably form two disulphide bonds. One of these proteins from Streptomyces nigrescens, is the well characterised metalloproteinase inhibitor SMPI.[9][10]
The structure of SMPI has been determined. It has 102 amino acid residues with two disulphide bridges and specifically inhibits metalloproteinases such as thermolysin, which belongs to MEROPS peptidase family M4. SMPI is composed of two beta-sheets, each consisting of four antiparallel beta-strands. The structure can be considered as two Greek key motifs with 2-fold internal symmetry, a Greek key beta-barrel. One unique structural feature found in SMPI is in its extension between the first and second strands of the second Greek key motif which is known to be involved in the inhibitory activity of SMPI. In the absence of sequence similarity, the SMPI structure shows clear similarity to both domains of the eye lens crystallins, both domains of the calcium sensor protein-S, as well as the single-domain yeast killer toxin. The yeast killer toxin structure was thought to be a precursor of the two-domain beta gamma-crystallin proteins, because of its structural similarity to each domain of the beta gamma-crystallins. SMPI thus provides another example of a single-domain protein structure that corresponds to the ancestral fold from which the two-domain proteins in the beta gamma-crystallin superfamily are believed to have evolved.[11]
Inhibitor I42
| Chagasin family peptidase inhibitor I42 | |||||||||
|---|---|---|---|---|---|---|---|---|---|
 solution structure of the trypanosoma cruzi cysteine protease inhibitor chagasin | |||||||||
| Identifiers | |||||||||
| Symbol | Inhibitor_I42 | ||||||||
| Pfam | PF09394 | ||||||||
| InterPro | IPR018990 | ||||||||
| MEROPS | I42 | ||||||||
| |||||||||
Inhibitor family I42 includes chagasin, a reversible inhibitor of papain-like cysteine proteases.[12] Chagasin has a beta-barrel structure, which is a unique variant of the immunoglobulin fold with homology to human CD8alpha.[13][14]
Inhibitor I48
| Peptidase inhibitor clitocypin | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| Identifiers | |||||||||
| Symbol | Inhibitor_I48 | ||||||||
| Pfam | PF10467 | ||||||||
| InterPro | IPR019508 | ||||||||
| MEROPS | I48 | ||||||||
| |||||||||
Inhibitor family I48 includes clitocypin, which binds and inhibits cysteine proteinases. It has no similarity to any other known cysteine proteinase inhibitors but bears some similarity to a lectin-like family of proteins from mushrooms.[15]
Inhibitor I53
| Thrombin inhibitor Madanin | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| Identifiers | |||||||||
| Symbol | Inhibitor_I53 | ||||||||
| Pfam | PF11714 | ||||||||
| InterPro | IPR021716 | ||||||||
| MEROPS | I53 | ||||||||
| |||||||||
Members of this family are the peptidase inhibitor madanin proteins. These proteins were isolated from tick saliva.[16]
Inhibitor I67
| Bromelain inhibitor VI | |||||||||
|---|---|---|---|---|---|---|---|---|---|
 nmr structure of bromelain inhibitor vi from pineapple stem | |||||||||
| Identifiers | |||||||||
| Symbol | Inhibitor_I67 | ||||||||
| Pfam | PF11405 | ||||||||
| InterPro | IPR022713 | ||||||||
| MEROPS | I67 | ||||||||
| |||||||||
Bromelain inhibitor VI, in the Inhibitor I67 family, is a double-chain inhibitor consisting of an 11-residue and a 41-residue chain.
Inhibitor I68
| Carboxypeptidase inhibitor I68 | |||||||||
|---|---|---|---|---|---|---|---|---|---|
 crystal structure of the tick carboxypeptidase inhibitor in complex with human carboxypeptidase b | |||||||||
| Identifiers | |||||||||
| Symbol | Inhibitor_I68 | ||||||||
| Pfam | PF10468 | ||||||||
| InterPro | IPR019509 | ||||||||
| MEROPS | I68 | ||||||||
| |||||||||
The Carboxypeptidase inhibitor I68 family represents a family of tick carboxypetidase inhibitors.
Inhibitor I78
| Peptidase inhibitor I78 family | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| Identifiers | |||||||||
| Symbol | Inhibitor_I78 | ||||||||
| Pfam | PF11720 | ||||||||
| Pfam clan | CL0367 | ||||||||
| InterPro | IPR021719 | ||||||||
| MEROPS | I78 | ||||||||
| |||||||||
The peptidase inhibitor I78 family includes Aspergillus elastase inhibitor.
Compounds
- Aprotinin
- Bestatin
- Calpain inhibitor I and II
- Chymostatin
- E-64
- Leupeptin (N-acetyl-L-leucyl-L-leucyl-L-argininal)
- alpha-2-Macroglobulin
- Pefabloc SC
- Pepstatin
- PMSF (phenylmethanesulfonyl fluoride)
- TLCK
- Trypsin inhibitors
See also
References
- ^ "antiprotease". The Free Dictionary.
- ^ OMIM - PROTEASE INHIBITOR 1; PI
- ^ Rawlings ND, Tolle DP, Barrett AJ (March 2004). "Evolutionary families of peptidase inhibitors". Biochem. J. 378 (Pt 3): 705–16. doi:10.1042/BJ20031825. PMC 1224039. PMID 14705960.
- ^ Tangrea MA, Bryan PN, Sari N, Orban J (July 2002). "Solution structure of the pro-hormone convertase 1 pro-domain from Mus musculus". J. Mol. Biol. 320 (4): 801–12. doi:10.1016/S0022-2836(02)00543-0. PMID 12095256.
- ^ Jain SC, Shinde U, Li Y, Inouye M, Berman HM (November 1998). "The crystal structure of an autoprocessed Ser221Cys-subtilisin E-propeptide complex at 2.0 A resolution". J. Mol. Biol. 284 (1): 137–44. doi:10.1006/jmbi.1998.2161. PMID 9811547.
- ^ Groves MR, Taylor MA, Scott M, Cummings NJ, Pickersgill RW, Jenkins JA (October 1996). "The prosequence of procaricain forms an alpha-helical domain that prevents access to the substrate-binding cleft". Structure. 4 (10): 1193–203. doi:10.1016/s0969-2126(96)00127-x. PMID 8939744.
- ^ Olonen A, Kalkkinen N, Paulin L (July 2003). "A new type of cysteine proteinase inhibitor--the salarin gene from Atlantic salmon (Salmo salar L.) and Arctic charr (Salvelinus alpinus)". Biochimie. 85 (7): 677–81. doi:10.1016/S0300-9084(03)00128-7. PMID 14505823.
- ^ Green TB, Ganesh O, Perry K, Smith L, Phylip LH, Logan TM, Hagen SJ, Dunn BM, Edison AS (April 2004). "IA3, an aspartic proteinase inhibitor from Saccharomyces cerevisiae, is intrinsically unstructured in solution". Biochemistry. 43 (14): 4071–81. doi:10.1021/bi034823n. PMID 15065849.
- ^ Tanaka K, Aoki H, Oda K, Murao S, Saito H, Takahashi H (November 1990). "Nucleotide sequence of the gene for a metalloproteinase inhibitor of Streptomyces nigrescens (SMPI)". Nucleic Acids Res. 18 (21): 6433. doi:10.1093/nar/18.21.6433. PMC 332545. PMID 2243793.
- ^ Murai H, Hara S, Ikenaka T, Oda K, Murao S (January 1985). "Amino acid sequence of Streptomyces metallo-proteinase inhibitor from Streptomyces nigrescens TK-23". J. Biochem. 97 (1): 173–80. PMID 3888972.
- ^ Ohno A, Tate S, Seeram SS, Hiraga K, Swindells MB, Oda K, Kainosho M (September 1998). "NMR structure of the Streptomyces metalloproteinase inhibitor, SMPI, isolated from Streptomyces nigrescens TK-23: another example of an ancestral beta gamma-crystallin precursor structure". J. Mol. Biol. 282 (2): 421–33. doi:10.1006/jmbi.1998.2022. PMID 9735297.
- ^ Monteiro AC, Abrahamson M, Lima AP, Vannier-Santos MA, Scharfstein J (November 2001). "Identification, characterization and localization of chagasin, a tight-binding cysteine protease inhibitor in Trypanosoma cruzi". J. Cell Sci. 114 (Pt 21): 3933–42. PMID 11719560.
- ^ Figueiredo da Silva AA; de Carvalho Vieira L; Krieger MA; Goldenberg S; Zanchin NI; Guimarães BG (February 2007). "Crystal structure of chagasin, the endogenous cysteine-protease inhibitor from Trypanosoma cruzi". J. Struct. Biol. 157 (2): 416–23. doi:10.1016/j.jsb.2006.07.017. PMID 17011790.
- ^ Wang SX, Pandey KC, Scharfstein J, Whisstock J, Huang RK, Jacobelli J, Fletterick RJ, Rosenthal PJ, Abrahamson M, Brinen LS, Rossi A, Sali A, McKerrow JH (May 2007). "The structure of chagasin in complex with a cysteine protease clarifies the binding mode and evolution of an inhibitor family". Structure. 15 (5): 535–43. doi:10.1016/j.str.2007.03.012. PMID 17502099.
- ^ Brzin J, Rogelj B, Popovic T, Strukelj B, Ritonja A (June 2000). "Clitocypin, a new type of cysteine proteinase inhibitor from fruit bodies of mushroom clitocybe nebularis". J. Biol. Chem. 275 (26): 20104–9. doi:10.1074/jbc.M001392200. PMID 10748021.
- ^ Iwanaga S, Okada M, Isawa H, Morita A, Yuda M, Chinzei Y (May 2003). "Identification and characterization of novel salivary thrombin inhibitors from the ixodidae tick, Haemaphysalis longicornis". Eur. J. Biochem. 270 (9): 1926–34. doi:10.1046/j.1432-1033.2003.03560.x. PMID 12709051.
External links
This page is based on a Wikipedia article. The text is available under the Creative Commons Attribution/Share-Alike License.
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.
Peptidase inhibitor I9 Provide feedback
This family includes the proteinase B inhibitor from Saccharomyces cerevisiae and the activation peptides from peptidases of the subtilisin family. The subtilisin propeptides are known to function as molecular chaperones, assisting in the folding of the mature peptidase [1] but have also been shown to act as 'temporary inhibitors' [2].
Literature references
-
Li Y, Hu Z, Jordan F, Inouye M; , J Biol Chem. 1995;270:25127-25132.: Functional analysis of the propeptide of subtilisin E as an intramolecular chaperone for protein folding. Refolding and inhibitory abilities of propeptide mutants. PUBMED:7559646 EPMC:7559646
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Kojima S, Minagawa T, Miura K; , FEBS Lett. 1997;411:128-132.: The propeptide of subtilisin BPN' as a temporary inhibitor and effect of an amino acid replacement on its inhibitory activity. PUBMED:9247157 EPMC:9247157
Internal database links
| SCOOP: | Peptidase_S8 Tk-SP_N-pro |
External database links
| MEROPS: | I9 |
| SCOP: | 1gns |
This tab holds annotation information from the InterPro database.
InterPro entry IPR010259
Proteinase propeptide inhibitors (sometimes refered to as activation peptides) are responsible for the modulation of folding and activity of the pro-enzyme or zymogen. The pro-segment docks into the enzyme moiety shielding the substrate binding site, thereby promoting inhibition of the enzyme. Several such propeptides share a similar topology [PUBMED:12095256], despite often low sequence identities [PUBMED:9811547]. The propeptide region has an open-sandwich antiparallel-alpha/antiparallel-beta fold, with two alpha-helices and four beta-strands with a (beta/alpha/beta)x2 topology.
This entry represents the propeptide domain at the N terminus of peptidases belonging to MEROPS family S8A, subtilisins. The subtilisin propeptides are known to function as molecular chaperones, assisting in the folding of the mature peptidase [PUBMED:7559646]. The propeptide is removed by proteolytic cleavage; removal activating the enzyme. This domain is also found in members of MEROPS proteinase inhibitor family I9.
Domain organisation
Below is a listing of the unique domain organisations or architectures in which this domain is found. More...
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Pfam Clan
This family is a member of clan PPP-I (CL0570), which has the following description:
This superfamily is characterised by families of short N-terminal domains such as the pancreatic carboxypeptidase activation domain, the subtilase propeptides/inhibitors, the prohormone convertase 1 pro-domain, and the peptidase- S8 pro-domain. All families exbhibit an alpha+beta sandwich with antiparallel beta-sheets in a (beta-alpha-beta)x2 conformation.
The clan contains the following 6 members:
Inhibitor_I9 Pro-kuma_activ Pro_sub2 Propep_M14 S8_pro-domain Tk-SP_N-proAlignments
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...
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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.
| Seed (77) |
Full (10147) |
Representative proteomes | UniProt (17270) |
NCBI (26048) |
Meta (68) |
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|---|---|---|---|---|---|---|---|---|---|
| RP15 (1907) |
RP35 (6141) |
RP55 (8867) |
RP75 (11276) |
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| Jalview | |||||||||
| HTML | |||||||||
| PP/heatmap | 1 | ||||||||
1Cannot generate PP/Heatmap alignments for seeds; no PP data available
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| Seed (77) |
Full (10147) |
Representative proteomes | UniProt (17270) |
NCBI (26048) |
Meta (68) |
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|---|---|---|---|---|---|---|---|---|---|
| RP15 (1907) |
RP35 (6141) |
RP55 (8867) |
RP75 (11276) |
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| Raw Stockholm | |||||||||
| Gzipped | |||||||||
You can also download a FASTA format file containing the full-length sequences for all sequences in the full alignment.
HMM logo
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...
Trees
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.
Curation
| Seed source: | Pfam-B_52 (release 8.0) |
| Previous IDs: | Subtilisin_N; |
| Type: | Domain |
| Sequence Ontology: | SO:0000417 |
| Author: |
Yeats C 
|
| Number in seed: | 77 |
| Number in full: | 10147 |
| Average length of the domain: | 81.30 aa |
| Average identity of full alignment: | 20 % |
| Average coverage of the sequence by the domain: | 12.84 % |
HMM information
| HMM build commands: |
build method: hmmbuild -o /dev/null HMM SEED
search method: hmmsearch -Z 45638612 -E 1000 --cpu 4 HMM pfamseq
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| Model details: |
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| Model length: | 82 | ||||||||||||
| Family (HMM) version: | 16 | ||||||||||||
| Download: | download the raw HMM for this family |
Species distribution
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Colour assignments
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Interactions
Structures
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 Inhibitor_I9 domain has been found. There are 39 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 sequence.
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