All families / PF01595
PF01595: CNNM
Cyclin M transmembrane N-terminal domain
- Curation status
- SEEDED
- Seed status
- EX DUF
- Characterization
- UNSCORED
Grounding
PF01595: Cyclin M transmembrane N-terminal domain
IPR002550: integrated entry for Cyclin M transmembrane N-terminal domain
Source description
This transmembrane domain is found in metal transporter proteins such as cyclin M 1/2 (CNNM). CNNMs are integral membrane proteins that are conserved from bacteria to humans. CNNM family members influence metal ion homeostasis through mechanisms that may not involve direct membrane transport of the ions. Structurally, CNNMs are complex proteins that contain an extracellular N-terminal domain preceding a transmembrane domain, a 'Bateman module', which consists of two cystathionine- beta-synthase (CBS) domains PF00571 (Pfam entry), and a C-terminal cNMP (cyclic nucleotide monophosphate) binding domain [InterPro reference PUB00088668,InterPro reference PUB00088669,InterPro reference PUB00088670,InterPro reference PUB00088671]. This entry describes the CNNM transmembrane domain which contains four hydrophobic regions and forms a dimer through hydrophobic contacts between TM2 and TM3, in which each chain is composed of three transmembrane helices (TM1-3), a pair of short helices exposed on the intracellular side, and a juxtamembrane (JM) helix that forms a belt-like structure [InterPro reference PUB00088669,InterPro reference PUB00098586]. The homodimer adopts an inward-facing conformation with a negatively charged cavity containing a conserved pi-helical turn in TM3 that coordinates a Mg2 ion [InterPro reference PUB00098586].
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
16 verified sequence examples. FASTA
| UniProt | Protein / organism | Sequence | Provenance |
|---|---|---|---|
| A0A131MCZ8 | Metal transporter cnnm-3 Caenorhabditis elegans | 797 aa; version 1 UniProt 2026_03 | PTM REGISTRY MIRROR9 sibling references
|
| A3QM97 | Metal transporter cnnm-1 Caenorhabditis elegans | 811 aa; version 1 UniProt 2026_03 | UNIPROT FETCH |
| G5ED05 | Metal transporter cnnm-5 Caenorhabditis elegans | 722 aa; version 1 UniProt 2026_03 | UNIPROT FETCH |
| P0AE45 | Polyamine export protein Escherichia coli (strain K12) | 447 aa; version 1 UniProt 2026_03 | UNIPROT FETCH1 sibling references |
| Q0GA42 | Metal transporter CNNM1 Mus musculus | 951 aa; version 5 UniProt 2026_03 | UNIPROT FETCH1 sibling references |
| Q12296 | Protein MAM3 Saccharomyces cerevisiae (strain ATCC 204508 / S288c) | 706 aa; version 1 UniProt 2026_03 | UNIPROT FETCH1 sibling references |
| Q17586 | Metal transporter cnnm-4 Caenorhabditis elegans | 467 aa; version 3 UniProt 2026_03 | UNIPROT FETCH |
| Q4V3C7 | DUF21 domain-containing protein At4g14230 Arabidopsis thaliana | 495 aa; version 1 UniProt 2026_03 | UNIPROT FETCH |
| Q67XQ0 | DUF21 domain-containing protein At4g14240 Arabidopsis thaliana | 494 aa; version 1 UniProt 2026_03 | UNIPROT FETCH |
| Q69ZF7 | Metal transporter CNNM4 Mus musculus | 771 aa; version 2 UniProt 2026_03 | UNIPROT FETCH1 sibling references |
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
- 56,844
- matches
- 56,920
- proteomes
- 21,107
- taxa
- 33,615
- structures
- 4
- alphafold models
- 38,019
- domain architectures
- 249
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.