P16033 · PSBA2_SYNY3

Function

function

Photosystem II (PSII) is a light-driven water:plastoquinone oxidoreductase that uses light energy to abstract electrons from H2O, generating O2 and a proton gradient subsequently used for ATP formation. It consists of a core antenna complex that captures photons, and an electron transfer chain that converts photonic excitation into a charge separation. The D1/D2 (PsbA/PsbD) reaction center heterodimer binds P680, the primary electron donor of PSII as well as several subsequent electron acceptors.

Miscellaneous

Cyanobacteria usually contain more than 2 copies of the psbA gene.
2 of the reaction center chlorophylls (ChlD1 and ChlD2) are entirely coordinated by water.
Herbicides such as atrazine, BNT, diuron or ioxynil bind in the Q(B) binding site and block subsequent electron transfer.

Catalytic activity

Cofactor

Note: The D1/D2 heterodimer binds P680, chlorophylls that are the primary electron donor of PSII, and subsequent electron acceptors. It shares a non-heme iron and each subunit binds pheophytin, quinone, additional chlorophylls, carotenoids and lipids. D1 provides most of the ligands for the Mn4-Ca-O5 cluster of the oxygen-evolving complex (OEC). There is also a Cl-1 ion associated with D1 and D2, which is required for oxygen evolution. The PSII complex binds additional chlorophylls, carotenoids and specific lipids.

Features

Showing features for binding site, site.

TypeIDPosition(s)Description
Binding site118Mg (UniProtKB | ChEBI) of chlorophyll a ChlzD1 (UniProtKB | ChEBI); axial binding residue
Binding site126pheophytin a D1 (UniProtKB | ChEBI)
Binding site147pheophytin a D1 (UniProtKB | ChEBI)
Site161Tyrosine radical intermediate
Binding site170[CaMn4O5] cluster (UniProtKB | ChEBI)
Binding site189[CaMn4O5] cluster (UniProtKB | ChEBI)
Site190Stabilizes free radical intermediate
Binding site198Mg (UniProtKB | ChEBI) of chlorophyll a PD1 (UniProtKB | ChEBI); axial binding residue
Binding site215a quinone B (UniProtKB | ChEBI)
Binding site215Fe cation (UniProtKB | ChEBI); ligand shared with heterodimeric partner
Binding site264a quinone B (UniProtKB | ChEBI)
Binding site265a quinone B (UniProtKB | ChEBI)
Binding site272Fe cation (UniProtKB | ChEBI); ligand shared with heterodimeric partner
Binding site332[CaMn4O5] cluster (UniProtKB | ChEBI)
Binding site333[CaMn4O5] cluster (UniProtKB | ChEBI)
Binding site337[CaMn4O5] cluster (UniProtKB | ChEBI)
Binding site342[CaMn4O5] cluster (UniProtKB | ChEBI)
Binding site344[CaMn4O5] cluster (UniProtKB | ChEBI)
Site344-345Cleavage; by CtpA

GO annotations

AspectTerm
Cellular Componentplasma membrane-derived thylakoid membrane
Cellular Componentplasma membrane-derived thylakoid photosystem II
Molecular Functionchlorophyll binding
Molecular Functionelectron transporter, transferring electrons within the cyclic electron transport pathway of photosynthesis activity
Molecular Functioniron ion binding
Molecular Functionoxidoreductase activity, acting on diphenols and related substances as donors, oxygen as acceptor
Molecular Functionoxygen evolving activity
Biological Processphotosynthetic electron transport in photosystem II
Biological Processresponse to herbicide

Keywords

Enzyme and pathway databases

Protein family/group databases

Names & Taxonomy

Protein names

  • Recommended name
    Photosystem II protein D1 2
  • EC number
  • Short names
    PSII D1 protein 2
  • Alternative names
    • Photosystem II Q(B) protein 2

Gene names

    • Name
      psbA2
    • Synonyms
      psbA-2
    • Ordered locus names
      slr1311
    • Name
      psbA3
    • Synonyms
      psbA-3
    • Ordered locus names
      sll1867

Organism names

Accessions

  • Primary accession
    P16033

Proteomes

Subcellular Location

Cellular thylakoid membrane
; Multi-pass membrane protein

Features

Showing features for topological domain, transmembrane.

TypeIDPosition(s)Description
Topological domain1-31Cytoplasmic
Transmembrane32-53Helical
Topological domain54-110Lumenal, thylakoid
Transmembrane111-134Helical
Topological domain135-142Cytoplasmic
Transmembrane143-161Helical
Topological domain162-191Lumenal, thylakoid
Transmembrane192-218Helical
Topological domain219-270Cytoplasmic
Transmembrane271-295Helical
Topological domain296-360Lumenal, thylakoid

Keywords

Phenotypes & Variants

Features

Showing features for mutagenesis.

TypeIDPosition(s)Description
Mutagenesis221-222Strong herbicide resistance.
Mutagenesis227-228Herbicide resistance.
Mutagenesis237Weak herbicide resistance.
Mutagenesis238Weak herbicide resistance.
Mutagenesis255Herbicide resistance.
Mutagenesis257Herbicide resistance.
Mutagenesis264Strong herbicide resistance.
Mutagenesis271Herbicide resistance.

PTM/Processing

Features

Showing features for chain, propeptide.

TypeIDPosition(s)Description
ChainPRO_00000904931-344Photosystem II protein D1 2
PropeptidePRO_0000316429345-360

Post-translational modification

C-terminally processed by CtpA; processing is essential to allow assembly of the oxygen-evolving complex and photosynthetic growth.
Tyr-161 forms a radical intermediate that is referred to as redox-active TyrZ, YZ or Y-Z.

Proteomic databases

Interaction

Subunit

PSII is composed of 1 copy each of membrane proteins PsbA, PsbB, PsbC, PsbD, PsbE, PsbF, PsbH, PsbI, PsbJ, PsbK, PsbL, PsbM, PsbT, PsbX, PsbY, PsbZ, Psb30/Ycf12, peripheral proteins PsbO, CyanoQ (PsbQ), PsbU, PsbV and a large number of cofactors. It forms dimeric complexes.

Protein-protein interaction databases

Family & Domains

Sequence similarities

Belongs to the reaction center PufL/M/PsbA/D family.

Keywords

Phylogenomic databases

Family and domain databases

Sequence

  • Sequence status
    Complete
  • Sequence processing
    The displayed sequence is further processed into a mature form.
  • Length
    360
  • Mass (Da)
    39,721
  • Last updated
    1990-04-01 v1
  • Checksum
    2FE4088498A416C2
MTTTLQQRESASLWEQFCQWVTSTNNRIYVGWFGTLMIPTLLTATTCFIIAFIAAPPVDIDGIREPVAGSLLYGNNIISGAVVPSSNAIGLHFYPIWEAASLDEWLYNGGPYQLVVFHFLIGIFCYMGRQWELSYRLGMRPWICVAYSAPVSAATAVFLIYPIGQGSFSDGMPLGISGTFNFMIVFQAEHNILMHPFHMLGVAGVFGGSLFSAMHGSLVTSSLVRETTEVESQNYGYKFGQEEETYNIVAAHGYFGRLIFQYASFNNSRSLHFFLGAWPVIGIWFTAMGVSTMAFNLNGFNFNQSILDSQGRVIGTWADVLNRANIGFEVMHERNAHNFPLDLASGEQAPVALTAPAVNG

Keywords

Sequence databases

Nucleotide SequenceProtein SequenceMolecule TypeStatus
X56000
EMBL· GenBank· DDBJ
CAA39472.1
EMBL· GenBank· DDBJ
Genomic DNA
X13547
EMBL· GenBank· DDBJ
CAA31899.1
EMBL· GenBank· DDBJ
Genomic DNA
BA000022
EMBL· GenBank· DDBJ
BAA18230.1
EMBL· GenBank· DDBJ
Genomic DNA
BA000022
EMBL· GenBank· DDBJ
BAA16586.1
EMBL· GenBank· DDBJ
Genomic DNA

Genome annotation databases

Similar Proteins

Disclaimer

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