CNNM, transmembrane domain (IPR002550)

Short name: CNNM

Overlapping homologous superfamilies


Domain relationships



Proteins containing the ancient conserved domain protein/cyclin M (CNNM) 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, and a C-terminal cNMP (cyclic nucleotide monophosphate) binding domain [PMID: 15498024, PMID: 22399287, PMID: 27856537, PMID: 27899452].

The CNNM transmembrane domain contains four hydrophobic regions. The second one is the shortest and the least hydrophobic, indicating that the second hydrophobic region might not be completely membrane-spanning, but instead forms a re-entrant loop. Hence, the CNNM integral membrane domain has been proposed to contain three full membrane-spanning regions and an additional re-entrant loop [PMID: 22399287].

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.
PROSITE profiles