sentences:  The catalytic core of the helicase is composed of six minichromosome maintenance (Mcm2-7) proteins, forming a hexameric ring.Away from DNA, the Mcm2-7 proteins form a single heterohexamer and are loaded in an inactive form at origins of DNA replication as a head-to-head double hexamers around double-stranded DNA.The Mcm proteins are recruited to replication origins then redistributed throughout the genomic DNA during S phase, indicative of their localization to the replication fork.