protein kinase C conserved region 1 (C1 domain) found in male germ cell RacGap (MgcRacGAP) and similar proteins
MgcRacGAP, also called Rac GTPase-activating protein 1 (RACGAP1) or protein CYK4, plays an important dual role in cytokinesis: i) it is part of centralspindlin-complex, together with the mitotic kinesin MKLP1, which is critical for the structure of the central spindle by promoting microtuble bundling; and ii) after phosphorylation by aurora B, MgcRacGAP becomes an effective regulator of RhoA and plays an important role in the assembly of the contractile ring and the initiation of cytokinesis. MgcRacGAP-like proteins contain an N-terminal C1 domain, and a C-terminal RhoGAP domain. This model corresponds to the C1 domain. The C1 domain is a cysteine-rich zinc binding domain that does not bind DNA nor possess structural similarity to conventional zinc finger domains; it contains two separate Zn(2+)-binding sites.