Interactions between two catalytically distinct MCM subgroups are essential for coordinated ATP hydrolysis and DNA replication.
The six MCM (minichromosome maintenance) proteins are essential DNA replication factors that each contain a putative ATP binding motif and together form a heterohexameric complex. We show that these motifs are required for viability in vivo and coordinated ATP hydrolysis in vitro. Mutational analysis discriminates between two functionally distinct MCM protein subgroups: Mcm4p, 6p, and 7p contribute canonical ATP binding motifs essential for catalysis, whereas the related motifs in Mcm2p, 3p, and 5p serve a regulatory function. Reconstitution experiments indicate that specific functional interactions between these two subgroups are required for robust ATP hydrolysis. Our observations show parallels between the MCM complex and the F1-ATPase, and we discuss how ATP hydrolysis by the MCM complex might be coupled to DNA strand separation.
Schwacha
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Howard Hughes Medical Institute, Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
Bell
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SP
D000251:Adenosine Triphosphatases / Q000737:chemistry / Q000378:metabolism*; D000255:Adenosine Triphosphate / Q000378:metabolism*; D020816:Amino Acid Motifs; D004261:DNA Replication / Q000502:physiology*; D005434:Flow Cytometry; D006868:Hydrolysis; D046911:Macromolecular Substances; D026341:Minichromosome Maintenance 1 Protein / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D021122:Protein Subunits; D006180:Proton-Translocating ATPases / Q000378:metabolism; D012568:Schizosaccharomyces / Q000235:genetics / Q000378:metabolism
D046911:Macromolecular Substances; D026341:Minichromosome Maintenance 1 Protein; D021122:Protein Subunits; D000255:Adenosine Triphosphate; D000251:Adenosine Triphosphatases; D006180:Proton-Translocating ATPases