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Bacterial photosystem II reaction centre, L and M subunits superfamily

SCOP classification
Root:   SCOP hierarchy in SUPERFAMILY [ 0] (11)
Class:   Membrane and cell surface proteins and peptides [ 56835] (58)
Fold:   Bacterial photosystem II reaction centre, L and M subunits [ 81484]
Superfamily:   Bacterial photosystem II reaction centre, L and M subunits [ 81483]
Families:   Bacterial photosystem II reaction centre, L and M subunits [ 81482] (4)


Superfamily statistics
Genomes (177) Uniprot 2018_03 genome PDB chains (SCOP 1.75)
Domains 763 24,454 38
Proteins 761 24,386 38


Functional annotation
General category Metabolism
Detailed category Photosynthesis

Document:
Function annotation of SCOP domain superfamilies

Enzyme Commission (EC)

(show details)
EC termFDR (all)SDEO levelAnnotation (direct or inherited)
Enzyme Commission (EC)Oxidoreductases0Least InformativeDirect
Enzyme Commission (EC)With oxygen as acceptor0Highly InformativeDirect

Document: EC annotation of SCOP domains

Enzyme Commission (EC)

(show details)
EC termFDR (all)SDEC levelAnnotation (direct or inherited)
Enzyme Commission (EC)Oxidoreductases0Least InformativeDirect

Document: EC annotation of SCOP domains

InterPro annotation
Cross references IPR000484 SSF81483 Protein matches
Abstract

This entry describes the photosynthetic reaction centre L and M subunits, and the homologous D1 (PsbA) and D2 (PsbD) photosystem II (PSII) reaction centre proteins from cyanobacteria, algae and plants. The D1 and D2 proteins only show approximately 15% sequence homology with the L and M subunits, however the conserved amino acids correspond to the binding sites of the phytochemically active cofactors. As a result, the reaction centres (RCs) of purple photosynthetic bacteria and PSII display considerable structural similarity in terms of cofactor organisation.

The D1 and D2 proteins occur as a heterodimer that form the reaction core of PSII, a multisubunit protein-pigment complex containing over forty different cofactors, which are anchored in the cell membrane in cyanobacteria, and in the thylakoid membrane in algae and plants. Upon absorption of light energy, the D1/D2 heterodimer undergoes charge separation, and the electrons are transferred from the primary donor (chlorophyll żaż) via pheophytin to the primary acceptor quinone Qa, then to the secondary acceptor Qb, which like the bacterial system, culminates in the production of ATP. However, PSII has an additional function over the bacterial system. At the oxidising side of PSII, a redox-active residue in the D1 protein reduces P680, the oxidised tyrosine then withdrawing electrons from a manganese cluster, which in turn withdraw electrons from water, leading to the splitting of water and the formation of molecular oxygen. PSII thus provides a source of electrons that can be used by photosystem I to produce the reducing power (NADPH) required to convert CO2 to glucose [PubMed12518057, PubMed14871485].


InterPro database


PDBeMotif information about ligands, sequence and structure motifs
Cross references PDB entries
Ligand binding statistics
Nucleic-acid binding statistics
Occurrence of secondary structure elements
Occurrence of small 3D structural motifs

PDBeMotif resource

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Internal database links

Browse genome assignments for this superfamily. The SUPERFAMILY hidden Markov model library has been used to carry out SCOP domain assignments to all genomes at the superfamily level.


Alignments of sequences to 10 models in this superfamily are available by clicking on the 'Alignments' icon above. PDB sequences less than 40% identical are shown by default, but any other sequence(s) may be aligned. Select PDB sequences, genome sequences, or paste in or upload your own sequences.


Browse and view proteins in genomes which have different domain combinations including a Bacterial photosystem II reaction centre, L and M subunits domain.


Examine the distribution of domain superfamilies, or families, across the major taxonomic kingdoms or genomes within a kingdom. This gives an immediate impression of how superfamilies, or families, are restricted to certain kingdoms of life.


Explore domain occurrence network where nodes represent genomes and edges are domain architectures (shared between genomes) containing the superfamily of interest.

There are 10 hidden Markov models representing the Bacterial photosystem II reaction centre, L and M subunits superfamily. Information on how the models are built, and plots showing hydrophobicity, match emmission probabilities and insertion/deletion probabilities can be inspected.


Jump to [ Top of page · SCOP classification · InterPro annotation · PDBeMotif links · Functional annotation · Enzyme Commission (EC) · Enzyme Commission (EC) · Internal database links ]