Summary: BtpA family
This is the Wikipedia entry entitled "BtpA protein". 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 firstname.lastname@example.org 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.
BtpA protein Edit Wikipedia article
In molecular biology, the BtpA protein family is a family of proteins which includes BtpA. BtpA appears to play a role in the stabilisation of photosystem I . It is an extrinsic membrane protein located on the cytoplasmic side of the thylakoid membrane. Homologs of BtpA are found in the crenarchaeota and euryarchaeota, where their function remains unknown. The Ycf4 protein is firmly associated with the thylakoid membrane, presumably through a transmembrane domain. Ycf4 co-fractionates with a protein complex larger than PSI upon sucrose density gradient centrifugation of solubilised thylakoids. The Ycf3 protein is loosely associated with the thylakoid membrane and can be released from the membrane with sodium carbonate. This suggests that Ycf3 is not part of a stable complex and that it probably interacts transiently with its partners. Ycf3 contains a number of tetratricopeptide repeats (TPR); TPR is a structural motif present in a wide range of proteins, which mediates protein-protein interactions.
- Zak E, Pakrasi HB (May 2000). "The BtpA protein stabilizes the reaction center proteins of photosystem I in the cyanobacterium Synechocystis sp. PCC 6803 at low temperature". Plant Physiol. 123 (1): 215â22. doi:10.1104/pp.123.1.215. PMC 58995. PMID 10806238.
- Zak E, Norling B, Andersson B, Pakrasi HB (April 1999). "Subcellular localization of the BtpA protein in the cyanobacterium Synechocystis sp. PCC 6803". Eur. J. Biochem. 261 (1): 311â6. doi:10.1046/j.1432-1327.1999.00281.x. PMID 10103064.
- Boudreau E, Takahashi Y, Lemieux C, Turmel M, Rochaix JD (October 1997). "The chloroplast ycf3 and ycf4 open reading frames of Chlamydomonas reinhardtii are required for the accumulation of the photosystem I complex". EMBO J. 16 (20): 6095â104. doi:10.1093/emboj/16.20.6095. PMC 1326293. PMID 9321389.
- Naver H, Boudreau E, Rochaix JD (December 2001). "Functional studies of Ycf3: its role in assembly of photosystem I and interactions with some of its subunits". Plant Cell 13 (12): 2731â45. doi:10.2307/3871531. PMC 139485. PMID 11752384.
BtpA family Provide feedback
The BtpA protein is tightly associated with the thylakoid membranes, where it stabilises the reaction centre proteins of photosystem I.
Zak E, Pakrasi HB; , Plant Physiol 2000;123:215-222.: The BtpA protein stabilizes the reaction center proteins of photosystem I in the cyanobacterium Synechocystis sp. PCC 6803 at low temperature. PUBMED:10806238 EPMC:10806238
Internal database links
|SCOOP:||CutC DUF561 DUF1341 DUF4743|
External database links
This tab holds annotation information from the InterPro database.
InterPro entry IPR005137
Photosystem I (PSI) is a large protein complex embedded within the photosynthetic thylakoid membrane. It consists of 11 subunits, ~100 chlorophyll a molecules, 2 phylloquinones, and 3 Fe4S4-clusters. The three dimensional structure of the PSI complex has been resolved at 2.5 A [PUBMED:11418848], which allows the precise localisation of each cofactor. PSI together with photosystem II (PSII) catalyses the light-induced steps in oxygenic photosynthesis - a process found in cyanobacteria, eukaryotic algae (e.g. red algae, green algae) and higher plants.
To date, three thylakoid proteins involved in the stable accumulation of PSI have been identified: BtpA [PUBMED:9045660], Ycf3 [PUBMED:9321389, PUBMED:9314531], and Ycf4 (INTERPRO) [PUBMED:9321389]. Because translation of the psaA and psaB mRNAs encoding the two reaction centre polypeptides, of PSI and PSII respectively, is not affected in mutant strains lacking functional ycf3 and ycf4, the products of these two genes appear to act at a post-translational step of PSI biosynthesis. These gene products are therefore involved either in the stabilisation or in the assembly of the PSI complex. However, their exact roles remain unknown. The BtpA protein appears to act at the level of PSI stabilisation [PUBMED:10806238]. It is an extrinsic membrane protein located on the cytoplasmic side of the thylakoid membrane [PUBMED:10103064, PUBMED:10806238]. Homologs of BtpA are found in the crenarchaeota and euryarchaeota, where their function remains unknown. The Ycf4 protein is firmly associated with the thylakoid membrane, presumably through a transmembrane domain [PUBMED:9321389]. Ycf4 co-fractionates with a protein complex larger than PSI upon sucrose density gradient centrifugation of solubilised thylakoids [PUBMED:9321389]. The Ycf3 protein is loosely associated with the thylakoid membrane and can be released from the membrane with sodium carbonate. This suggests that Ycf3 is not part of a stable complex and that it probably interacts transiently with its partners [PUBMED:11752384]. Ycf3 contains a number of tetratrico peptide repeats (TPR, INTERPRO); TPR is a structural motif present in a wide range of proteins, which mediates protein-protein interactions.
- 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
- the UniProt description of the protein sequence
- the number of residues in the sequence
- the Pfam graphic itself.
Loading domain graphics...
This large superfamily of TIM barrel enzymes all contain a common phosphate binding site. The phosphate is found in a variety of cofactors and ligands such as FMN [1,2].
The clan contains the following 57 members:Ala_racemase_N ALAD Aldolase AP_endonuc_2 BtpA CdhD CutC DAHP_synth_1 DAHP_synth_2 DeoC DHDPS DHO_dh DHquinase_I DUF1341 DUF2090 DUF556 DUF561 DUF692 DUF993 Dus F_bP_aldolase FMN_dh G3P_antiterm Glu_syn_central Glu_synthase His_biosynth HMGL-like IGPS IMPDH Lys-AminoMut_A MtrH NanE NAPRTase NeuB NMO OAM_alpha OMPdecase Orn_Arg_deC_N Oxidored_FMN PcrB PdxJ PRAI Pterin_bind QRPTase_C Radical_SAM RhaA Ribul_P_3_epim SOR_SNZ Tagatose_6_P_K ThiC_Rad_SAM ThiG TIM TMP-TENI Transaldolase Trp_syntA UvdE UxuA
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 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:
- Pfam viewer
- an HTML-based viewer that uses DAS to retrieve alignment fragments on request
1Cannot generate PP/Heatmap alignments for seeds; no PP data available
Key: available, not generated, — not available.
Format an alignment
If you find these logos useful in your own work, please consider citing the following article:
Note: You can also download the data file for the tree.
Curation and family details
|Seed source:||Pfam-B_4453 (release 6.6)|
|Number in seed:||5|
|Number in full:||2514|
|Average length of the domain:||248.10 aa|
|Average identity of full alignment:||45 %|
|Average coverage of the sequence by the domain:||94.04 %|
|HMM build commands:||
build method: hmmbuild -o /dev/null HMM SEED
search method: hmmsearch -Z 80369284 -E 1000 --cpu 4 HMM pfamseq
|Family (HMM) version:||11|
|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
How the sunburst is generated
Colouring and labels
Anomalies in the taxonomy tree
Missing taxonomic levels
Unmapped species names
Too many species/sequences
The tree shows the occurrence of this domain across different species. More...
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