The MCM2-7 complex consists of six closely related proteins that are highly conserved throughout the eukaryotic kingdom. In eukaryotes, Mcm5 is a component of the MCM2-7 complex (MCM complex), which consists of six sequence-related AAA + type ATPases/helicases that form a hetero-hexameric ring []. MCM2-7 complex is part of the pre-replication complex (pre-RC). In G1 phase, inactive MCM2-7 complex is loaded onto origins of DNA replication [, , ]. During G1-S phase, MCM2-7 complex is activated to unwind the double stranded DNA and plays an important role in DNA replication forks elongation [].The components of the MCM2-7 complex are: DNA replication licensing factor MCM2, DNA replication licensing factor MCM3, DNA replication licensing factor MCM4, DNA replication licensing factor MCM5, DNA replication licensing factor MCM6, DNA replication licensing factor MCM7,
Melanophilin, also termed SlaC2-a, or exophilin-3, is a GTP-bound form of Rab27A-, myosin Va-, and actin-binding protein present on melanosomes. It is involved in the control of transferring of melanosomes from microtubules to actin filaments. It also functions as a melanocyte type myosin Va (McM5) binding partner and directly activates the actin-activated ATPase activity of McM5 through forming a tripartite protein complex with Rab27A and an actin-based motor myosin Va [,]. SlaC2-a belongs to the Slp homologue lacking C2 domains (Slac2) family. It contains an N-terminal Slp homology domain (SHD), but lacks tandem C2 domains. The SHD consists of two conserved regions, designated SHD1 (Slp homology domain 1) and SHD2, which may function as protein interaction sites []. The SHD1 and SHD2 of SlaC2-a are separated by a putative FYVE zinc finger, which resembles a FYVE-related domain that is structurally similar to the canonical FYVE domains but lacks the three signature sequences: an N-terminal WxxD motif (x for any residue), the central basic R(R/K)HHCRxCG patch, and a C-terminal RVC motif. Moreover, Slac2-a has a middle myosin-binding domain and a C-terminal actin-binding domain [].
