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P09144 (PSAB_CHLRE) Reviewed, UniProtKB/Swiss-Prot

Last modified May 14, 2014. Version 125. Feed History...

Clusters with 100%, 90%, 50% identity | Documents (1) | Third-party data text xml rdf/xml gff fasta
to top of pageNames·Attributes·General annotation·Ontologies·Sequence annotation·Sequences·References·Cross-refs·Entry info·DocumentsCustomize order

Names and origin

Protein namesRecommended name:
Photosystem I P700 chlorophyll a apoprotein A2

EC=1.97.1.12
Alternative name(s):
PSI-B
PsaB
Gene names
Name:psaB
Synonyms:ps1a2
Encoded onPlastid; Chloroplast
OrganismChlamydomonas reinhardtii (Chlamydomonas smithii) [Reference proteome]
Taxonomic identifier3055 [NCBI]
Taxonomic lineageEukaryotaViridiplantaeChlorophytaChlorophyceaeChlamydomonadalesChlamydomonadaceaeChlamydomonas

Protein attributes

Sequence length735 AA.
Sequence statusComplete.
Protein existenceEvidence at protein level

General annotation (Comments)

Function

PsaA and PsaB bind P700, the primary electron donor of photosystem I (PSI), as well as the electron acceptors A0, A1 and FX. 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. Oxidized P700 is reduced on the lumenal side of the thylakoid membrane by plastocyanin or cytochrome c6. HAMAP-Rule MF_00482

Both potential cofactor branches in PSI seem to be active; however, electron transfer seems to proceed preferentially down the path including the phylloquinone bound by PsaA. HAMAP-Rule MF_00482

Catalytic activity

Reduced plastocyanin + oxidized ferredoxin + light = oxidized plastocyanin + reduced ferredoxin. HAMAP-Rule MF_00482

Cofactor

P700 is a chlorophyll a/chlorophyll a' dimer, A0 is one or more chlorophyll a, A1 is one or both phylloquinones and FX is a shared 4Fe-4S iron-sulfur center By similarity.

Subunit structure

The PsaA/B heterodimer binds the P700 chlorophyll special pair and subsequent electron acceptors. PSI consists of a core antenna complex that captures photons, and an electron transfer chain that converts photonic excitation into a charge separation. The eukaryotic PSI reaction center is composed of at least 11 subunits.

Subcellular location

Plastidchloroplast thylakoid membrane; Multi-pass membrane protein HAMAP-Rule MF_00482.

Sequence similarities

Belongs to the PsaA/PsaB family.

Sequence annotation (Features)

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifier

Molecule processing

Chain1 – 735735Photosystem I P700 chlorophyll a apoprotein A2 HAMAP-Rule MF_00482
PRO_0000088609

Regions

Transmembrane47 – 7024Helical; Name=I; Potential
Transmembrane136 – 15924Helical; Name=II; Potential
Transmembrane176 – 20025Helical; Name=III; Potential
Transmembrane274 – 29219Helical; Name=IV; Potential
Transmembrane331 – 35424Helical; Name=V; Potential
Transmembrane370 – 39627Helical; Name=VI; Potential
Transmembrane418 – 44023Helical; Name=VII; Potential
Transmembrane518 – 53619Helical; Name=VIII; Potential
Transmembrane576 – 59722Helical; Name=IX; Potential
Transmembrane644 – 66623Helical; Name=X; Potential
Transmembrane708 – 72821Helical; Name=XI; Potential

Sites

Metal binding5601Iron-sulfur (4Fe-4S); shared with dimeric partner
Metal binding5691Iron-sulfur (4Fe-4S); shared with dimeric partner By similarity
Metal binding6551Magnesium (chlorophyll-a B1 axial ligand; P700 special pair)
Metal binding6631Magnesium (chlorophyll-a B3 axial ligand) By similarity
Binding site6711Chlorophyll-a B3 By similarity
Binding site6721Phylloquinone B

Experimental info

Mutagenesis5591P → A or L: Assembles functional PSI. Reaction center is somewhat unstable and interaction with psaC is impaired. The LEU mutant is less stable than the ALA mutant. Ref.8 Ref.11 Ref.13 Ref.15
Mutagenesis5601C → H: Loss of PSI assembly and function. Ref.8 Ref.11 Ref.13 Ref.15
Mutagenesis5611D → N: Loss of PSI assembly and function. Ref.9 Ref.11 Ref.13 Ref.15
Mutagenesis5631P → L: Assembles functional PSI. Reaction center is somewhat unstable and interaction with psaC is impaired. Ref.9 Ref.11 Ref.13 Ref.15
Mutagenesis5651R → E: Loss of PSI assembly and function. Ref.9 Ref.11 Ref.13 Ref.15
Mutagenesis6551H → C, G, N or S: Contains somewhat decreased amounts of PSI, depending on the strain; significantly changes the spin density of the P700+ cation radical. Ref.10 Ref.11 Ref.12 Ref.13 Ref.15
Mutagenesis6551H → D: Very little PSI detected. Ref.10 Ref.11 Ref.12 Ref.13 Ref.15
Mutagenesis6551H → F or L: Loss of P700 function. Ref.10 Ref.11 Ref.12 Ref.13 Ref.15
Mutagenesis6551H → Q: Impairment of P700 function. More severe; when associated with Q-676 in psaA. Ref.10 Ref.11 Ref.12 Ref.13 Ref.15
Mutagenesis6551H → R: No PSI detected. Ref.10 Ref.11 Ref.12 Ref.13 Ref.15
Mutagenesis6721W → F: Still able to photoaccumulate an electron on A1. Ref.11 Ref.13 Ref.15
Sequence conflict151Q → R in CAA29287. Ref.1
Sequence conflict181T → A in CAA29287. Ref.1
Sequence conflict211R → I in CAA29287. Ref.1
Sequence conflict37 – 382GM → VW in CAA29287. Ref.1
Sequence conflict48 – 492FA → IS in CAA29287. Ref.1
Sequence conflict891A → C in CAA29287. Ref.1
Sequence conflict2031S → LQ in CAA29287. Ref.1
Sequence conflict2981I → N in CAA29287. Ref.1
Sequence conflict3351L → I in CAA29287. Ref.1
Sequence conflict5151P → L Ref.1
Sequence conflict5151P → L Ref.5

Sequences

Sequence LengthMass (Da)Tools
P09144 [UniParc].

Last modified March 28, 2003. Version 4.
Checksum: 82F9914CE07A7908

FASTA73582,109
        10         20         30         40         50         60 
MATKLFPKFS QGLAQDPTTR RIWYGLAMAH DFESHDGMTE ENLYQKIFAS HFGQLSIIFL 

        70         80         90        100        110        120 
WTSGNLFHVA WQGNFEQWVT DPVHIRPIAH AIWDPHFGQP AVEAFTRGGA SGPVNISTSG 

       130        140        150        160        170        180 
VYQWWYTIGM RTNQDLYVGS VFLALVSAIF LFAGWLHLQP NFQPSLSWFK DAESRLNHHL 

       190        200        210        220        230        240 
SGLFGVSSLA WTGHLVHVAI PESRGQHVGW DNFLSVLPHP QGLTPFFTGN WAAYAQSPDT 

       250        260        270        280        290        300 
ASHVFGTAQG SGQAILTFLG GFHPQTQSLW LTDMAHHHLA IAVIFIVAGH MYRTNFGIGH 

       310        320        330        340        350        360 
RMQAILEAHT PPSGSLGAGH KGLFDTVNNS LHFQLGLALA SVGTITSLVA QHMYSLPPYA 

       370        380        390        400        410        420 
FQAIDFTTQA ALYTHHQYIA GFIMCGAFAH GAIFFIRDYD PEQNKGNVLA RMLDHKEALI 

       430        440        450        460        470        480 
SHLSWVSLFL GFHTLGLYVH NDVMQAFGTP EKQILIEPVF AQWIQAAHGK ALYGFDFLLS 

       490        500        510        520        530        540 
SKTSAAFANG QSLWLPGWLD AINNNQNSLF LTIGPGDFLV HHAIALGLHT TTLILVKGAL 

       550        560        570        580        590        600 
DARGSKLMPD KKDFGYSFPC DGPGRGGTCD ISAYDAFYLA VFWMLNTIGW VTFYWHWKHL 

       610        620        630        640        650        660 
TLWQGNVAQF DESSTYLMGW LRDYLWLNSS QLINGYNPFG MNSLSVWAWT FLFGHLIYAT 

       670        680        690        700        710        720 
GFMFLISWRG YWQELIETLV WAHEKTPLAN LVYWKDKPVA LSIVQARLVG LAHFSVGYIF 

       730 
TYAAFLIAST SGRFG 

« Hide

References

« Hide 'large scale' references
[1]"Structural and transcription analysis of two homologous genes for the P700 chlorophyll a-apoproteins in Chlamydomonas reinhardtii: evidence for in vivo trans-splicing."
Kueck U., Choquet Y., Schneider M., Dron M., Bennoun P.
EMBO J. 6:2185-2195(1987) [PubMed] [Europe PMC] [Abstract]
Cited for: NUCLEOTIDE SEQUENCE [GENOMIC DNA].
Strain: CC-406.
[2]"Revised sequence of the Chlamydomonas reinhardtii chloroplast gene psaB."
Forsyth A.M., Redding K., Purton S.
Submitted (NOV-2002) to the EMBL/GenBank/DDBJ databases
Cited for: NUCLEOTIDE SEQUENCE [GENOMIC DNA].
[3]"Nucleotide diversity of the Chlamydomonas reinhardtii plastid genome: addressing the mutational-hazard hypothesis."
Smith D.R., Lee R.W.
BMC Evol. Biol. 9:120-120(2009) [PubMed] [Europe PMC] [Abstract]
Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
Strain: CC-503.
[4]"Origin and evolution of the colonial Volvocales (Chlorophyceae) as inferred from multiple, chloroplast gene sequences."
Nozaki H., Misawa K., Kajita T., Kato M., Nohara S., Watanabe M.M.
Mol. Phylogenet. Evol. 17:256-268(2000) [PubMed] [Europe PMC] [Abstract]
Cited for: NUCLEOTIDE SEQUENCE [GENOMIC DNA] OF 80-578.
Strain: 137c / CC-125.
[5]"Sequence of the chloroplast DNA region of Chlamydomonas reinhardii containing the gene of the large subunit of ribulose bisphosphate carboxylase and parts of its flanking genes."
Dron M., Rahire M., Rochaix J.-D.
J. Mol. Biol. 162:775-793(1982) [PubMed] [Europe PMC] [Abstract]
Cited for: NUCLEOTIDE SEQUENCE [GENOMIC DNA] OF 493-735.
[6]"Transformation of chloroplasts with the psaB gene encoding a polypeptide of the photosystem I reaction center."
Bingham S.E., Xu R.H., Webber A.N.
FEBS Lett. 292:137-140(1991) [PubMed] [Europe PMC] [Abstract]
Cited for: PARTIAL NUCLEOTIDE SEQUENCE [GENOMIC DNA] (MUTANT AC-U-G-2.3).
Strain: CC-2341.
[7]"The Chlamydomonas reinhardtii plastid chromosome: islands of genes in a sea of repeats."
Maul J.E., Lilly J.W., Cui L., dePamphilis C.W., Miller W., Harris E.H., Stern D.B.
Plant Cell 14:2659-2679(2002) [PubMed] [Europe PMC] [Abstract]
Cited for: IDENTIFICATION, COMPLETE PLASTID GENOME.
[8]"Site-directed mutagenesis of the photosystem I reaction center in chloroplasts. The proline-cysteine motif."
Webber A.N., Gibbs P.B., Ward J.B., Bingham S.E.
J. Biol. Chem. 268:12990-12995(1993) [PubMed] [Europe PMC] [Abstract]
Cited for: MUTAGENESIS OF PRO-559 AND CYS-560.
Strain: 137c / CC-125 and CC-2341.
[9]"Evidence that the FX domain in photosystem I interacts with the subunit PsaC: site-directed changes in PsaB destabilize the subunit interaction in Chlamydomonas reinhardtii."
Rodday S.M., Webber A.N., Bingham S.E., Biggins J.
Biochemistry 34:6328-6334(1995) [PubMed] [Europe PMC] [Abstract]
Cited for: MUTAGENESIS OF ASP-561; PRO-563 AND ARG-565.
Strain: 137c / CC-125.
[10]"Site-directed mutations affecting the spectroscopic characteristics and midpoint potential of the primary donor in photosystem I."
Webber A.N., Su H., Bingham S.E., Kaess H., Krabben L., Kuhn M., Jordan R., Schlodder E., Lubitz W.
Biochemistry 35:12857-12863(1996) [PubMed] [Europe PMC] [Abstract]
Cited for: MUTAGENESIS OF HIS-655.
Strain: FuD7.
[11]"A systematic survey of conserved histidines in the core subunits of photosystem I by site-directed mutagenesis reveals the likely axial ligands of P700."
Redding K., MacMillan F., Leibl W., Brettel K., Hanley J., Rutherford A.W., Breton J., Rochaix J.-D.
EMBO J. 17:50-60(1998) [PubMed] [Europe PMC] [Abstract]
Cited for: MUTAGENESIS OF CONSERVED HISTIDINES.
Strain: 137c / CC-125.
[12]"Influence of the axial ligands on the spectral properties of P700 of photosystem I: a study of site-directed mutants."
Krabben L., Schlodder E., Jordan R., Carbonera D., Giacometti G., Lee H., Webber A.N., Lubitz W.
Biochemistry 39:13012-13025(2000) [PubMed] [Europe PMC] [Abstract]
Cited for: MUTAGENESIS OF HIS-655.
Strain: CC-2696.
[13]"Evidence for two active branches for electron transfer in photosystem I."
Guergova-Kuras M., Boudreaux B., Joliot A., Joliot P., Redding K.
Proc. Natl. Acad. Sci. U.S.A. 98:4437-4442(2001) [PubMed] [Europe PMC] [Abstract]
Cited for: MUTAGENESIS OF A1 PHYLLOQUINONE LIGANDS.
Strain: 137c / CC-125.
[14]"Reversed-phase HPLC determination of chlorophyll a' and phylloquinone in photosystem I of oxygenic photosynthetic organisms."
Nakamura A., Akai M., Yoshida E., Taki T., Watanabe T.
Eur. J. Biochem. 270:2446-2458(2003) [PubMed] [Europe PMC] [Abstract]
Cited for: PRESENCE OF CHLOROPHYLL A' IN PSI.
Strain: IAM C-9.
[15]"Mutations in both sides of the photosystem I reaction center identify the phylloquinone observed by electron paramagnetic resonance spectroscopy."
Boudreaux B., MacMillan F., Teutloff C., Agalarov R., Gu F., Grimaldi S., Bittl R., Brettel K., Redding K.
J. Biol. Chem. 276:37299-37306(2001) [PubMed] [Europe PMC] [Abstract]
Cited for: MUTAGENESIS OF A1 PHYLLOQUINONE LIGANDS.
Strain: 137c / CC-125.

Cross-references

Sequence databases

EMBL
GenBank
DDBJ
X05848 Genomic DNA. Translation: CAA29287.1.
U57326 Genomic DNA. Translation: AAN78307.1.
FJ423446 Genomic DNA. Translation: ACJ50135.1.
AB044470 Genomic DNA. Translation: BAB18396.1.
J01399 Genomic DNA. No translation available.
S67792 Genomic DNA. Translation: AAB20423.2.
BK000554 Genomic DNA. Translation: DAA00949.2.
PIRB28341.
S18319.
RefSeqNP_958404.1. NC_005353.1.

3D structure databases

ProteinModelPortalP09144.
SMRP09144. Positions 2-734.
ModBaseSearch...
MobiDBSearch...

Protein-protein interaction databases

IntActP09144. 4 interactions.

Proteomic databases

PRIDEP09144.

Protocols and materials databases

StructuralBiologyKnowledgebaseSearch...

Genome annotation databases

EnsemblPlantsDAA00949; DAA00949; DAA00949.
GeneID2717038.
KEGGcre:ChreCp048.

Phylogenomic databases

KOK02690.

Enzyme and pathway databases

BioCycCHLAMY:CHRECP048-MONOMER.
MetaCyc:CHRECP048-MONOMER.

Family and domain databases

Gene3D1.20.1130.10. 1 hit.
HAMAPMF_00482. PSI_PsaB.
InterProIPR001280. PSI_PsaA/B.
IPR020586. PSI_PsaA/B_CS.
IPR006244. PSI_PsaB.
[Graphical view]
PfamPF00223. PsaA_PsaB. 1 hit.
[Graphical view]
PIRSFPIRSF002905. PSI_A. 1 hit.
PRINTSPR00257. PHOTSYSPSAAB.
SUPFAMSSF81558. SSF81558. 1 hit.
TIGRFAMsTIGR01336. psaB. 1 hit.
PROSITEPS00419. PHOTOSYSTEM_I_PSAAB. 1 hit.
[Graphical view]
ProtoNetSearch...

Entry information

Entry namePSAB_CHLRE
AccessionPrimary (citable) accession number: P09144
Secondary accession number(s): B7U1I8 expand/collapse secondary AC list , Q36714, Q8HR52, Q9GH44
Entry history
Integrated into UniProtKB/Swiss-Prot: July 1, 1989
Last sequence update: March 28, 2003
Last modified: May 14, 2014
This is version 125 of the entry and version 4 of the sequence. [Complete history]
Entry statusReviewed (UniProtKB/Swiss-Prot)
Annotation programPlant Protein Annotation Program

Relevant documents

SIMILARITY comments

Index of protein domains and families