plasma membrane-derived thylakoid photosystem II

GO:0030096 · Energy complex · Multiprotein complex · Proposed

A photosystem II protein complex located in the plasma membrane-derived bacterial thylakoid that contains a P680 reaction center and catalyzes the water-oxidizing, plastoquinone-reducing step of oxygenic photosynthesis. [GO:0030096]

Synonyms: cyanobacterial PSII

Part of: plasma membrane-derived thylakoid membrane (GO:0031676)

UniProt location names: UniProt Consortium, CC BY 4.0. Reference label and route sources.

Taxonomic distribution

• NCBITaxon:1117 Cyanobacteriota — COMMON: Cyanobacteria with internal thylakoids carry PSII complexes in plasma membrane-derived thylakoid membranes as part of oxygenic photosynthetic electron transport. [DOI:10.1146/annurev-cellbio-120823-022747]

Canonical examples

• NCBITaxon:103690 Nostoc sp. PCC 7120 = FACHB-418 — Cyanobacterial model used for single-particle EM of intact phycobilisomes associated with photosystem II assemblies. [DOI:10.1038/cr.2015.59]

Functions

• photosynthetic electron transport chain GO:0009767 — Plasma membrane-derived thylakoid PSII begins cyanobacterial linear electron transport by oxidizing water and reducing plastoquinone.
  • GO:0030096 GO:0030096 defines plasma membrane-derived thylakoid photosystem II as a P680 reaction center complex in the bacterial thylakoid.
  • DOI:10.1146/annurev-cellbio-120823-022747 Perez-Boerema et al. 2024 review PSII as an upstream cyanobacterial thylakoid electron-transport complex.

Mechanism graphs

Phycobilisomes feed excitation into cyanobacterial PSII (FUNCTION)

In Nostoc, phycobilisomes associate with thylakoid photosystem II assemblies that initiate electron flow toward plastoquinone in the bacterial thylakoid membrane.

Discussions

• CURATION_TODO (OPEN): Resolve exact source-neutral component groundings for bona fide bacterial PSII core, antenna, and oxygen-evolving subfamilies before adding subunit-level component rows. GO exactly grounds the bacterial thylakoid PSII complex, but this record does not yet distinguish conserved PSII constituents from phycobilisome antenna proteins or PSII assembly and repair factors.

Evidence

• GO:0030096 Gene Ontology cellular-component term for plasma membrane-derived thylakoid photosystem II.
• GO:0009523 Gene Ontology cellular-component term for generic photosystem II.
• GO:0031676 Gene Ontology cellular-component term for the plasma membrane-derived thylakoid membrane that houses this cyanobacterial PSII complex.
• GO:0030075 Gene Ontology cellular-component term for bacterial thylakoid.
• GO:0009767 Gene Ontology biological-process term for the photosynthetic electron transport chain.
• DOI:10.1146/annurev-cellbio-120823-022747 Perez-Boerema et al. 2024, Evolution of Thylakoid Structural Diversity, Annual Review of Cell and Developmental Biology.
• DOI:10.1038/cr.2015.59 Chang et al. 2015, Structural organization of an intact phycobilisome and its association with photosystem II, Cell Research.

Curation history

• 2026-09-13T05:02:43Z codex · CREATED_RECORD — Scaffolded by scripts/new_record.py
• 2026-09-13T05:03:13Z codex · EXPANDED_RECORD — Added PSII synonymy, generic PSII parentage, bacterial thylakoid membrane parthood, cyanobacterial scope, a Nostoc example, photosynthetic electron-transport function, GO and literature evidence, a nonmechanistic PSII light-input graph, and a PSII subunit-boundary TODO.
• 2026-09-13T05:10:06Z codex · REVISED_RECORD — #752: removed the overbroad bare PSII synonym from the GO:0030096 record while retaining the scoped cyanobacterial PSII synonym.

Source: data/structures/energy_complex/plasma_membrane_derived_thylakoid_photosystem_ii.yaml