Mutations in subdomain B of the minichromosome maintenance (MCM) helicase affect DNA binding and modulate conformational transitions.

ABSTRACT: Minichromosome maintenance (MCM) proteins are believed to provide the replicative helicase activity in eukaryotes and archaea. The single MCM orthologue from Methanothermobacter thermautotrophicus (MthMCM) has been extensively characterized as a model of the eukaryotic heterohexameric MCM complex. MthMCM forms high molecular weight complexes in solution consistent with a dodecamer. Visualization of this complex by electron microscopy suggests that single and double heptameric or hexameric rings can form. We have mutated two arginine residues (Arg-137, Arg-160) in the N-terminal subdomain B of MthMCM based on their apparent potential to form inter-ring hydrogen bonds. Both the single R137A and the double R137A,R160A mutants were characterized by a combination of biophysical, biochemical, an

SUBMITTER: Jenkinson ER 

PROVIDER: S-EPMC2683335 | biostudies-literature | 2009 Feb

REPOSITORIES: biostudies-literature