Q31QV2 (PSAC_SYNE7) Reviewed, UniProtKB/Swiss-Prot

Names and origin

Protein names

Recommended name:
Photosystem I iron-sulfur center
EC=1.97.1.12

Alternative name(s):
9 kDa polypeptide
PSI-C
Photosystem I subunit VII
PsaC

Gene names

Name:	psaC
Ordered Locus Names:	Synpcc7942_0535

Organism

Synechococcus elongatus (strain PCC 7942) (Anacystis nidulans R2) [Complete proteome] [HAMAP]

Taxonomic identifier

1140 [NCBI]

Taxonomic lineage

cellular organisms › Bacteria › Cyanobacteria › Oscillatoriophycideae › Chroococcales › Synechococcus › Synechococcus elongatus

Protein attributes

Sequence length	81 AA.
Sequence status	Complete.
Sequence processing	The displayed sequence is further processed into a mature form.
Protein existence	Inferred from homology

General annotation (Comments)

Function	Apoprotein for the two 4Fe-4S centers FA and FB of photosystem I (PSI); essential for photochemical activity. FB is the terminal electron acceptor of PSI, donating electrons to ferredoxin. The C-terminus interacts with PsaA/B/D and helps assemble the protein into the PSI complex. Required for binding of PsaD and PsaE to PSI. PSI is a plastocyanin/cytochrome c6-ferredoxin oxidoreductase, converting photonic excitation into a charge separation, which transfers an electron from the donor P700 chlorophyll pair to the spectroscopically characterized acceptors A0, A1, FX, FA and FB in turn By similarity. HAMAP-Rule MF_01303
Catalytic activity	Reduced plastocyanin + oxidized ferredoxin + light = oxidized plastocyanin + reduced ferredoxin. HAMAP-Rule MF_01303
Cofactor	Binds 2 4Fe-4S clusters. Cluster 2 is most probably the spectroscopically characterized electron acceptor FA and cluster 1 is most probably FB By similarity.
Subunit structure	The cyanobacterial PSI reaction center is composed of one copy each of PsaA,B,C,D,E,F,I,J,K,L,M and X, and forms trimeric complexes By similarity.
Subcellular location	Cellular thylakoid membrane; Peripheral membrane protein; Cytoplasmic side By similarity HAMAP-Rule MF_01303.
Sequence similarities	Contains 2 4Fe-4S ferredoxin-type domains.

Ontologies

Keywords
Biological process	Electron transport Photosynthesis Transport
Cellular component	Membrane Photosystem I Thylakoid
Domain	Repeat
Ligand	4Fe-4S Iron Iron-sulfur Metal-binding
Molecular function	Oxidoreductase
Technical term	Complete proteome
Gene Ontology (GO)
Biological_process	photosynthetic electron transport in photosystem I Inferred from electronic annotation. Source: InterPro
Cellular_component	photosystem I Inferred from electronic annotation. Source: UniProtKB-KW thylakoid membrane Inferred from electronic annotation. Source: UniProtKB-SubCell
Molecular_function	4 iron, 4 sulfur cluster binding Inferred from electronic annotation. Source: UniProtKB-KW electron carrier activity Inferred from electronic annotation. Source: HAMAP metal ion binding Inferred from electronic annotation. Source: UniProtKB-KW oxidoreductase activity Inferred from electronic annotation. Source: UniProtKB-KW
Complete GO annotation...

Sequence annotation (Features)

	Feature key	Position(s)	Length	Description	Graphical view	Feature identifier
Molecule processing
	Initiator methionine	1	1	Removed By similarity
	Chain	2 – 81	80	Photosystem I iron-sulfur center HAMAP-Rule MF_01303		PRO_0000292107
Regions
	Domain	2 – 31	30	4Fe-4S ferredoxin-type 1
	Domain	39 – 68	30	4Fe-4S ferredoxin-type 2
Sites
	Metal binding	11	1	Iron-sulfur 1 (4Fe-4S) By similarity
	Metal binding	14	1	Iron-sulfur 1 (4Fe-4S) By similarity
	Metal binding	17	1	Iron-sulfur 1 (4Fe-4S) By similarity
	Metal binding	21	1	Iron-sulfur 2 (4Fe-4S) By similarity
	Metal binding	48	1	Iron-sulfur 2 (4Fe-4S) By similarity
	Metal binding	51	1	Iron-sulfur 2 (4Fe-4S) By similarity
	Metal binding	54	1	Iron-sulfur 2 (4Fe-4S) By similarity
	Metal binding	58	1	Iron-sulfur 1 (4Fe-4S) By similarity

Sequences

	Sequence		Length	Mass (Da)
	Q31QV2 [UniParc]. Last modified December 6, 2005. Version 1. Checksum: 40010FD9371A4AFB	FASTA	81	8,798
	10 20 30 40 50 60 MSHSVKIYDT CIGCTQCVRA CPLDVLEMVP WDGCKAGQIA ASPRTEDCVG CKRCETACPT 70 80 DFLSIRVYLG AETTRSMGLA Y

References

[1]

"Complete sequence of chromosome 1 of Synechococcus elongatus PCC 7942." US DOE Joint Genome Institute Copeland A., Lucas S., Lapidus A., Barry K., Detter J.C., Glavina T., Hammon N., Israni S., Pitluck S., Schmutz J., Larimer F., Land M., Kyrpides N., Lykidis A., Richardson P. Submitted (AUG-2005) to the EMBL/GenBank/DDBJ databases Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA]. Strain: PCC 7942.

Cross-references

Sequence databases
EMBL GenBank DDBJ	CP000100 Genomic DNA. Translation: ABB56567.1.
RefSeq	YP_399554.1. NC_007604.1.
3D structure databases
ProteinModelPortal	Q31QV2.
SMR	Q31QV2. Positions 2-81.
ModBase	Search...
Protein-protein interaction databases
STRING	1140.Synpcc7942_0535.
Protocols and materials databases
StructuralBiologyKnowledgebase	Search...
Genome annotation databases
EnsemblBacteria	ABB56567; ABB56567; Synpcc7942_0535.
GeneID	3774773.
KEGG	syf:Synpcc7942_0535.
PATRIC	23786185. VBISynElo51371_0636.
Organism-specific databases
CMR	Search...
Phylogenomic databases
eggNOG	COG1145.
HOGENOM	HOG000230505.
KO	K02691.
ProtClustDB	PRK02651.
Enzyme and pathway databases
BioCyc	MetaCyc:SYNPCC7942_0535-MONOMER. SELO1140:GJWQ-542-MONOMER.
Family and domain databases
HAMAP	MF_01303. PSI_PsaC.
InterPro	IPR001450. 4Fe4S-bd_dom. IPR017896. 4Fe4S_Fe-S-bd. IPR017900. 4Fe4S_Fe_S_CS. IPR017491. PSI_PsaC. [Graphical view]
Pfam	PF12838. Fer4_7. 1 hit. [Graphical view]
TIGRFAMs	TIGR03048. PS_I_psaC. 1 hit.
PROSITE	PS00198. 4FE4S_FER_1. 2 hits. PS51379. 4FE4S_FER_2. 2 hits. [Graphical view]
ProtoNet	Search...

Entry information

Entry name

PSAC_SYNE7

Accession

Primary (citable) accession number: Q31QV2

Entry history

Integrated into UniProtKB/Swiss-Prot:	June 26, 2007
Last sequence update:	December 6, 2005
Last modified:	May 1, 2013
This is version 61 of the entry and version 1 of the sequence. [Complete history]

Entry status

Reviewed (UniProtKB/Swiss-Prot)

Annotation program

Prokaryotic Protein Annotation Program