All families / PF11623
PF11623: NdhS
NAD(P)H dehydrogenase subunit S
- Curation status
- SEEDED
- Seed status
- EX DUF
- Characterization
- UNSCORED
Grounding
PF11623: NAD(P)H dehydrogenase subunit S
IPR021659: integrated entry for NAD(P)H dehydrogenase subunit S
Source description
This family is found in Bacteria and Streptophyta includes members such as NdhS (NAD(P)H-quinone oxidoreductase subunit S). NdhS, also known as CRR31 (chlororespiratory reduction 31), is a subunit of the chloroplast NADH dehydrogenase-like (NDH) complex [InterPro reference PUB00083363]. It is also a subunit of the cyanobacterial NDH-1 complex [InterPro reference PUB00083366] [InterPro reference PUB00083365]. NAD(P)H-oxidizing subunits have not been found in chloroplasts or cyanobacteria, where ferredoxin is probably the electron donor. NdhS contributes to the formation of a ferredoxin binding site of NDH [InterPro reference PUB00083363] and is necessary for high affinity binding of ferredoxin [InterPro reference PUB00083368]. The cyanobacterial NDH-1 complex, also known as NADPH:plastoquinone oxidoreductase or type I NAD(P)H dehydrogenase, is involved in plastoquinone reduction and cyclic electron transfer (CET) around photosystem I. The chloroplast NDH is more similar to cyanobacterial NDH-1, which is believed to be the origin of chloroplast NDH, than to mitochondrial NADH dehydrogenase present in the same species [InterPro reference PUB00083364] [InterPro reference PUB00083367]. The NDH complexes of chloroplasts, however, contain many subunits that are absent from cyanobacterial NDH-1 complexes.
Evidence and references
- InterPro entry and its literature references. PUB identifiers are internal InterPro references, not PubMed identifiers. Unresolved citations link to the originating entry.
- Frozen description source: InterPro/Pfam API
Source descriptions and links are provenance, not independent functional validation.
Evidence counts: not scored.
Curated functional assertions
No curated functional assertions supplied.
Protein sequence examples
1 verified sequence example. FASTA
| UniProt | Protein / organism | Sequence | Provenance |
|---|---|---|---|
| Q9T0A4 | NAD(P)H-quinone oxidoreductase subunit S, chloroplastic Arabidopsis thaliana | 250 aa; version 1 UniProt 2026_03 | PTM REGISTRY MIRROR |
Pfam membership is not functional evidence. Whole-protein sequences do not establish domain boundaries. A coverage gap here is not absence from UniProt.
Sequences and metadata: UniProt Consortium, CC BY 4.0.
Domain matches
No residue-level domain match evidence is available in this build. Structure and AlphaFold counters do not supply coordinates or establish function.
Snapshot counters
- proteins
- 721
- matches
- 721
- proteomes
- 581
- taxa
- 1,686
- structures
- 12
- alphafold models
- 546
- domain architectures
- 8
Classification basis
pfam previous unknown name
No scoring reasons supplied.
Related Mech records
This family joined the worklist after the frozen cross-Mech scan, so other Mechs were not searched for it. Missing links here are not evidence that other Mechs lack it; rows shown come from mentions of a former DUF/UPF name.
No cross-Mech examples are present in the supplied snapshot.
Curation history and reviews
No retained curation events supplied.
No retained review supplied.
Record source
Status and evidence
- Seed status
- A name-based classification of frozen InterPro/Pfam metadata. UNKNOWN CANDIDATE means the metadata explicitly says the function is unknown. KNOWN HISTORICAL DUF means a DUF name matched without that wording; this heuristic is not proof of a known function and does not establish experimental characterization. EX DUF means Pfam renamed the family away from a DUF/UPF name, as recorded in Pfam's previous identifiers; a rename usually follows published work on some members but is naming history, not proof of function for every member. Some EX DUF families' current names or descriptions still say the function is unknown; their classification basis lists this, and scoring does not treat them as characterized. FALSE POSITIVE TEXT HIT means the naming rules did not match.
- Characterization
- A separate evidence-scoring result. UNSCORED means no score has been calculated; it is not evidence that the family lacks a known function. Missing scores are not negative evidence. PARTIALLY CHARACTERIZED has partial support; KNOWN HISTORICAL DUF can inherit the seed label or reflect a known-function signal. Neither label implies experimental validation.
- Evidence counts
- Source-specific signals, not unique proteins, publications, or confidence scores. Known counts Rhea reactions and experimentally supported GO molecular-function annotations. Partial counts functional/domain assignments. Context counts structural, environmental, orthology, interaction and neighborhood signals; context alone does not assign function. Repeated annotations may not be independent.
- Curation status
- Reported separately from seed classification and characterization. SNAPSHOT ONLY means no curated metadata was supplied for this build. SEEDED denotes a source-derived record, not an expert-reviewed functional claim.
- Missing counts
- Not available means the source did not supply that counter. A zero is a reported count. Not scored means evidence counts are unavailable.