Class I myosin, motor domain (IPR036072)

Short name: MYSc_Myo1

Overlapping homologous superfamilies

Domain relationships


Class I myosins are present in a wide range of species from yeast to man, and have been implicated in actin cytoskeleton organization, cell motility, and endocytosis [PMID: 18344022, PMID: 27401928]. They are actin-dependent molecular motors that play important roles in muscle contraction, cell motility, and organelle transport. S. cerevisiae has two class I myosins, Myo3 and Myo5, whereas S. pombe has only Myo1 [PMID: 11294886]. Vertebrates have eight class I myosin genes, six of which encode short-tailed forms (Myo1a, b, c, d, g, and h) and two of which encode long-tailed forms (Myo1e, f) [PMID: 18344022]. Myosin I, an unconventional myosin, does not form dimers [PMID: 12471888].

Myosin I consist of a N-terminal motor domain, a C-terminal tail homology domain (TH1), and in some cases additional C-terminal structures that can mediate protein-protein interactions. The class 1 myosin motor domain contains motifs that are conserved across the myosin superfamily, including an actin binding cleft and a nucleotide binding pocket. When ATP is present, the motor has a low affinity for actin. Attachment to actin is accompanied by a force generating conformational change, referred to as a 'working stroke' [PMID: 20471271].

Contributing signatures

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