PF01256: Carb_kinase

NAD(P)H-hydrate dehydratase

Curation status: SEEDED
Seed status: EX DUF
Characterization: UNSCORED

Grounding

PF01256: NAD(P)H-hydrate dehydratase
IPR000631: integrated entry for NAD(P)H-hydrate dehydratase

Source description

Hydration of NAD(P)H to NAD(P)HX, which inhibits several dehydrogenases, is corrected by an ATP-dependent dehydratase and an epimerase. The ATP-dependent dehydratase has been identified as the product of the vertebrate Carkd (carbohydrate kinase domain) gene [InterPro reference PUB00073185,InterPro reference PUB00100876]. Variants of this enzyme leads to deficient NADHX repair mitochondrial dysfunction in humans, associated with a lethal neurometabolic disorder in early childhood [InterPro reference PUB00100876]. In E. coli, it is found as the C-terminal domain of a bifunctional enzyme (YjeF) that also includes the epimerase and uses ADP instead of ATP [InterPro reference PUB00060794]. These enzymes are widespread in eukaryotes, prokaryotes, and archaea.

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

12 verified sequence examples. FASTA

UniProt	Protein / organism	Sequence	Provenance
O67377	Bifunctional NAD(P)H-hydrate repair enzyme Nnr Aquifex aeolicus (strain VF5)	499 aa; version 1 UniProt 2026_03	UNIPROT FETCH 1 sibling references ProteinTraitsMech: PROSITE:PS01050
P31806	Bifunctional NAD(P)H-hydrate repair enzyme Nnr Escherichia coli (strain K12)	515 aa; version 2 UniProt 2026_03	PTM REGISTRY MIRROR 4 sibling references ProteinTraitsMech: Pfam:PF01256 ProteinTraitsMech: PROSITE:PS01049 ProteinTraitsMech: PROSITE:PS01050 ProteinTraitsMech: UniProtKB:P31806
P32740	ATP-dependent (S)-NAD(P)H-hydrate dehydratase Caenorhabditis elegans	307 aa; version 3 UniProt 2026_03	UNIPROT FETCH 6 sibling references ProteinTraitsMech: GO:0047453 ProteinTraitsMech: InterPro:IPR017953 ProteinTraitsMech: CDD:cd01171 ProteinTraitsMech: InterPro:IPR000631 ProteinTraitsMech: NCBIfam:TIGR00196 ProteinTraitsMech: PROSITE:PS51383
P36059	ATP-dependent (S)-NAD(P)H-hydrate dehydratase Saccharomyces cerevisiae (strain ATCC 204508 / S288c)	337 aa; version 1 UniProt 2026_03	UNIPROT FETCH 4 sibling references ProteinTraitsMech: GO:0047453 ProteinTraitsMech: InterPro:IPR017953 ProteinTraitsMech: PROSITE:PS01049 ProteinTraitsMech: PROSITE:PS01050
P37391	Bifunctional NAD(P)H-hydrate repair enzyme Nnr Mycobacterium leprae (strain TN)	473 aa; version 2 UniProt 2026_03	UNIPROT FETCH 1 sibling references ProteinTraitsMech: PROSITE:PS01050
P94368	ADP-dependent (S)-NAD(P)H-hydrate dehydratase Bacillus subtilis (strain 168)	276 aa; version 1 UniProt 2026_03	UNIPROT FETCH 11 sibling references ProteinTraitsMech: GO:0052855 ProteinTraitsMech: GO:0052856 ProteinTraitsMech: GO:0110051 ProteinTraitsMech: GO:0046496 ProteinTraitsMech: InterPro:IPR017953 ProteinTraitsMech: CDD:cd01171 ProteinTraitsMech: InterPro:IPR000631 ProteinTraitsMech: NCBIfam:TIGR00196 ProteinTraitsMech: PROSITE:PS01049 ProteinTraitsMech: PROSITE:PS01050 ProteinTraitsMech: PROSITE:PS51383
P9WF11	Bifunctional NAD(P)H-hydrate repair enzyme Nnr Mycobacterium tuberculosis (strain ATCC 25618 / H37Rv)	473 aa; version 1 UniProt 2026_03	UNIPROT FETCH 1 sibling references ProteinTraitsMech: PROSITE:PS01049
Q8IW45	ATP-dependent (S)-NAD(P)H-hydrate dehydratase Homo sapiens	347 aa; version 1 UniProt 2026_03	PTM REGISTRY MIRROR 9 sibling references ProteinTraitsMech: GO:0047453 ProteinTraitsMech: GO:0110051 ProteinTraitsMech: GO:0046496 ProteinTraitsMech: CDD:cd01171 ProteinTraitsMech: InterPro:IPR000631 ProteinTraitsMech: NCBIfam:TIGR00196 ProteinTraitsMech: Pfam:PF01256 ProteinTraitsMech: PROSITE:PS51383 ProteinTraitsMech: UniProtKB:Q8IW45
Q94AF2	ATP-dependent (S)-NAD(P)H-hydrate dehydratase Arabidopsis thaliana	365 aa; version 1 UniProt 2026_03	UNIPROT FETCH 6 sibling references ProteinTraitsMech: GO:0047453 ProteinTraitsMech: GO:0110051 ProteinTraitsMech: CDD:cd01171 ProteinTraitsMech: InterPro:IPR000631 ProteinTraitsMech: NCBIfam:TIGR00196 ProteinTraitsMech: PROSITE:PS51383
Q9CZ42	ATP-dependent (S)-NAD(P)H-hydrate dehydratase Mus musculus	343 aa; version 1 UniProt 2026_03	UNIPROT FETCH 6 sibling references ProteinTraitsMech: GO:0047453 ProteinTraitsMech: CDD:cd01171 ProteinTraitsMech: InterPro:IPR000631 ProteinTraitsMech: NCBIfam:TIGR00196 ProteinTraitsMech: Pfam:PF01256 ProteinTraitsMech: PROSITE:PS51383

First 10 shown; the FASTA and family JSON contain all examples.

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: 22,302
matches: 22,644
proteomes: 19,898
taxa: 32,358
structures: 37
alphafold models: 15,274
domain architectures: 88

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

data/families/PF01256.yaml
Family YAML in this build

Download this family (JSON)

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.