ATP binding and hydrolysis by Mcm2 regulate DNA binding by Mcm complexes.

ABSTRACT: The essential minichromosome maintenance (Mcm) proteins Mcm2 through Mcm7 likely comprise the replicative helicase in eukaryotes. In addition to Mcm2-7, other subcomplexes, including one comprising Mcm4, Mcm6, and Mcm7, unwind DNA. Using Mcm4/6/7 as a tool, we reveal a role for nucleotide binding by Saccharomyces cerevisiae Mcm2 in modulating DNA binding by Mcm complexes. Previous studies have shown that Mcm2 inhibits DNA unwinding by Mcm4/6/7. Here, we show that interaction of Mcm2 and Mcm4/6/7 is not sufficient for inhibition; rather, Mcm2 requires nucleotides for its regulatory role. An Mcm2 mutant that is defective for ATP hydrolysis (K549A), as well as ATP analogues, was used to show that ADP binding by Mcm2 is required to inhibit DNA binding and unwinding by Mcm4/6/7. This Mcm2-media

SUBMITTER: Stead BE 

PROVIDER: S-EPMC5154746 | biostudies-literature | 2009 Aug

REPOSITORIES: biostudies-literature