P69416 (PSAC_HORVU) 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

Encoded on

Plastid; Chloroplast

Organism

Hordeum vulgare (Barley)

Taxonomic identifier

4513 [NCBI]

Taxonomic lineage

cellular organisms › Eukaryota › Viridiplantae › Streptophyta › Streptophytina › Embryophyta › Tracheophyta › Euphyllophyta › Spermatophyta › Magnoliophyta › Liliopsida › commelinids › Poales › Poaceae › BEP clade › Pooideae › Triticeae › Hordeum

Protein attributes

Sequence length	81 AA.
Sequence status	Complete.
Sequence processing	The displayed sequence is further processed into a mature form.
Protein existence	Evidence at protein level

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-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. 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 eukaryotic PSI reaction center is composed of at least 11 subunits By similarity.
Subcellular location	Plastid › chloroplast thylakoid membrane; Peripheral membrane protein; Stromal 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	Chloroplast Membrane Photosystem I Plastid Thylakoid
Domain	Repeat
Ligand	4Fe-4S Iron Iron-sulfur Metal-binding
Molecular function	Oxidoreductase
Technical term	Direct protein sequencing
Gene Ontology (GO)
Biological_process	photosynthetic electron transport in photosystem I Inferred from electronic annotation. Source: InterPro
Cellular_component	chloroplast thylakoid membrane Inferred from electronic annotation. Source: UniProtKB-SubCell photosystem I Inferred from electronic annotation. Source: UniProtKB-KW
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 Ref.5 Ref.6
	Chain	2 – 81	80	Photosystem I iron-sulfur center HAMAP-Rule MF_01303		PRO_0000061984
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
Experimental info
	Mutagenesis	27 – 34	8	Missing in vitro PSI-C is unstably assembled into PSI cores in presence of PSI-D, and not at all in its absence. In vitro PSI-C is unable to bind to PSI cores even in the presence of PSI-D; when associated with 67-Y--Y-80 deleted. Ref.7 Ref.8
	Mutagenesis	68 – 81	14	YLGPE…MALSY → EMIPWDGC: Removes residues 26-33 and reinserts them at the C-terminus. In vitro the atypical presence of residues 26-33 re-enables the protein to assemble into PSI cores even in the absence of PSI-D. Ref.8
	Mutagenesis	68 – 81	14	Missing in vitro PSI-C is unable to bind to PSI cores even in the presence of PSI-D; when associated with 27-E--C-34. Ref.8

Sequences

	Sequence		Length	Mass (Da)
	P69416 [UniParc]. Last modified January 23, 2007. Version 2. Checksum: 681F63DC8FC603BF	FASTA	81	8,899
	10 20 30 40 50 60 MSHSVKIYDT CIGCTQCVRA CPTDVLEMIP WDGCKAKQIA SAPRTEDCVG CKRCESACPT 70 80 DFLSVRVYLG PETTRSMALS Y

References

	« Hide 'large scale' referencesShow 'large scale' references »
[1]	"A barley chloroplast clone encoding psaC and part of ndhD: RNA editing of the ndhD initiation codon in barley?" Okkels J.S., Moeller B.L. Submitted (NOV-1992) to the EMBL/GenBank/DDBJ databases Cited for: NUCLEOTIDE SEQUENCE [GENOMIC DNA]. Strain: cv. Svalofs Bonus.
[2]	"Transcripts of the ndhH-D operon of barley plastids: possible role of unedited site III in splicing of the ndhA intron." del Campo E.M., Sabater B., Martin M. Nucleic Acids Res. 28:1092-1098(2000) [PubMed] [Europe PMC] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [GENOMIC DNA]. Strain: cv. Hassan. Tissue: Leaf.
[3]	"Sequence variation of chloroplast psaC gene region occurred in some triticeae species." Ning S., Chen Q., Yuan Z., Zhang L., Liu D. Submitted (NOV-2006) to the EMBL/GenBank/DDBJ databases Cited for: NUCLEOTIDE SEQUENCE [GENOMIC DNA].
[4]	"Complete chloroplast genome sequences of Hordeum vulgare, Sorghum bicolor and Agrostis stolonifera, and comparative analyses with other grass genomes." Saski C., Lee S.-B., Fjellheim S., Guda C., Jansen R.K., Luo H., Tomkins J., Rognli O.A., Daniell H., Clarke J.L. Theor. Appl. Genet. 115:571-590(2007) [PubMed] [Europe PMC] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA]. Strain: cv. Morex.
[5]	"Amino acid sequence of the 9-kDa iron-sulfur protein of photosystem I in barley." Scheller H.V., Svendsen I., Moeller B.L. Carlsberg Res. Commun. 54:11-15(1989) [PubMed] [Europe PMC] [Abstract] Cited for: PROTEIN SEQUENCE OF 2-81.
[6]	"Identification of a chloroplast-encoded 9-kDa polypeptide as a 2[4Fe-4S] protein carrying centers A and B of photosystem I." Hoej P.B., Svendsen I., Scheller H.V., Moeller B.L. J. Biol. Chem. 262:12676-12684(1987) [PubMed] [Europe PMC] [Abstract] Cited for: PROTEIN SEQUENCE OF 2-30.
[7]	"Reconstitution of barley photosystem I with modified PSI-C allows identification of domains interacting with PSI-D and PSI-A/B." Naver H., Scott M.P., Golbeck J.H., Moeller B.L., Scheller H.V. J. Biol. Chem. 271:8996-9001(1996) [PubMed] [Europe PMC] [Abstract] Cited for: MUTAGENESIS OF 27-GLU--CYS-34.
[8]	"The eight-amino acid internal loop of PSI-C mediates association of low molecular mass iron-sulfur proteins with the P700-FX core in photosystem I." Naver H., Scott M.P., Golbeck J.H., Olsen C.E., Scheller H.V. J. Biol. Chem. 273:18778-18783(1998) [PubMed] [Europe PMC] [Abstract] Cited for: MUTAGENESIS OF 27-GLU--CYS-34 AND 68-TYR--TYR-81. Strain: cv. Svalofs Bonus.

Cross-references

Sequence databases
EMBL GenBank DDBJ	L06607 Genomic DNA. Translation: AAA32953.1. AJ011848 Genomic DNA. Translation: CAA09816.1. EF137813 Genomic DNA. Translation: ABL95204.1. EF115541 Genomic DNA. Translation: ABK79463.1.
PIR	A27375. A32364.
RefSeq	YP_874703.1. NC_008590.1.
3D structure databases
ProteinModelPortal	P69416.
ModBase	Search...
Protein-protein interaction databases
IntAct	P69416. 1 interaction.
Protocols and materials databases
StructuralBiologyKnowledgebase	Search...
Genome annotation databases
GeneID	4525168.
Organism-specific databases
Gramene	P69416.
Phylogenomic databases
ProtClustDB	CHL00065.
Gene expression databases
Genevestigator	P69416.
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_HORVU

Accession

Primary (citable) accession number: P69416
Secondary accession number(s): A1E9P1, P10794

Entry history

Integrated into UniProtKB/Swiss-Prot:	March 1, 2005
Last sequence update:	January 23, 2007
Last modified:	April 3, 2013
This is version 50 of the entry and version 2 of the sequence. [Complete history]

Entry status

Reviewed (UniProtKB/Swiss-Prot)

Annotation program

Plant Protein Annotation Program