The essential minichromosome maintenance proteins, Mcm2 through Mcm7 likely comprise the replicative helicase in eukaryotes. In addition to Mcm2-7, other sub-complexes, including one comprised of 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 nucleotide for its regulatory role. An Mcm2 mutant defective for ATP hydrolysis (K549A) as well as ATP analogues were used to show that ADP binding by Mcm2 is required to inhibit DNA binding and unwinding by Mcm4/6/7. This Mcm2-mediated regulation of Mcm4/6/7 is independent of Mcm3/5. Furthermore, the importance of ATP hydrolysis by Mcm2 to the regulation of the native complex was apparent from the altered DNA binding properties of Mcm2(KA)-7. Moreover, together with the finding that Mcm2(K549A) does not support yeast viability, these results indicate that the nucleotide bound state of Mcm2 is critical in regulating the activities of Mcm4/6/7 and Mcm2-7 complexes.
|Evidence ID||Analyze ID||Interactor||Interactor Systematic Name||Interactor||Interactor Systematic Name||Type||Assay||Annotation||Action||Modification||Phenotype||Source||Reference||Note|
|Evidence ID||Analyze ID||Gene||Gene Systematic Name||Gene Ontology Term||Gene Ontology Term ID||Qualifier||Aspect||Method||Evidence||Source||Assigned On||Reference||Annotation Extension|
|Evidence ID||Analyze ID||Gene||Gene Systematic Name||Phenotype||Experiment Type||Experiment Type Category||Mutant Information||Strain Background||Chemical||Details||Reference|
|Evidence ID||Analyze ID||Regulator||Regulator Systematic Name||Target||Target Systematic Name||Experiment||Conditions||Strain||Source||Reference|