[3][4] The minichromosome maintenance proteins were named after a yeast genetics screen for mutants defective in the regulation of DNA replication initiation.

[5] In archaea, the heterohexamer ring is replaced by a homohexamer made up of a single type mcm protein, pointing at a history of gene duplication and diversification.

[12][13] During the G1 phase of the cell cycle, Cdc6 is recruited by ORC to form a launching pad for the loading of two head-to-head Mcm2-7 hexamers, also known as the pre-replication complex (pre-RC).

Soluble Mcm2-7 hexamer forms a flexible left-handed open-ringed structure stabilised by Cdt1 prior to its loading onto chromatin,[2][17] one at a time.

[3] Once pre-RC formation is complete, Orc1-6 and Cdc6 are no longer required for MCM2-7 retention at the origin, and they are dispensable for subsequent DNA replication.

During S phase, Cdc6 and Cdt1 are degraded or inactivated to block additional pre-RC formation, and bidirectional DNA replication ensues.

As a critical mechanism to ensure only a single round of DNA replication, the loading of additional MCM2-7 complexes into pre-RCs is inactivated by redundant means after passage into S phase.

[27] In the absence of these proteins, dsDNA unwinding and replisome movement powered by MCM2-7 continue, but DNA synthesis stops.

[30][31] Regarding the physical mechanism of how a hexameric helicase unwinds DNA, two models have been proposed based on in vivo and in vitro data.

In the "pump" model, pairs of hexameric helicases unwind duplex DNA by either twisting it apart or extruding it through channels in the complex.

[32] The pump model postulates that multiple helicases load at replication origins, translocate away from one another, and in some manner eventually become anchored in place.

The association between MCMs and proliferation in cancer cell lines is mostly attributed to its ability to enhance DNA replication.