2vl6
From Proteopedia
STRUCTURAL ANALYSIS OF THE SULFOLOBUS SOLFATARICUS MCM PROTEIN N- TERMINAL DOMAIN
Structural highlights
FunctionMCM_SACS2 Presumptive replicative helicase. Has ATPase and DNA helicase activities. The latter preferentially melts 5'-tailed oligonucleotides and is stimulated by the SSB protein (single-stranded DNA binding protein). The active ATPase sites in the MCM ring are formed through the interaction surfaces of two neighboring subunits such that a critical structure of a conserved arginine finger motif is provided in trans relative to the ATP-binding site of the Walker A box of the adjacent subunit. The helicase function is proposed to use a partially sequential mode of ATP hydrolysis; the complex appears to tolerate multiple catalytically inactive subunits.[1] Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedThe Mini-Chromosome Maintenance (MCM) proteins are candidates of replicative DNA helicase in eukarya and archaea. Here we report a 2.8 A crystal structure of the N-terminal domain (residues 1-268) of the Sulfolobus solfataricus MCM (Sso MCM) protein. The structure reveals single-hexameric ring-like architecture, at variance from the protein of Methanothermobacter thermoautotrophicus (Mth). Moreover, the central channel in Sso MCM seems significantly narrower than the Mth counterpart, which appears to more favorably accommodate single-stranded DNA than double-stranded DNA, as supported by DNA-binding assays. Structural analysis also highlights the essential role played by the zinc-binding domain in the interaction with nucleic acids and allows us to speculate that the Sso MCM N-ter domain may function as a molecular clamp to grasp the single-stranded DNA passing through the central channel. On this basis possible DNA unwinding mechanisms are discussed. Structural analysis of the Sulfolobus solfataricus MCM protein N-terminal domain.,Liu W, Pucci B, Rossi M, Pisani FM, Ladenstein R Nucleic Acids Res. 2008 Jun;36(10):3235-43. Epub 2008 Apr 16. PMID:18417534[2] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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