2m45
From Proteopedia
NMR solution structure of the C-terminus of the minichromosome maintenance protein MCM from Sulfolobus solfataricus
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] Publication Abstract from PubMedThe minichromosome maintenance complex (MCM) represents the replicative DNA helicase both in eukaryotes and archaea. Here, we describe the solution structure of the C-terminal domains of the archaeal MCMs of Sulfolobus solfataricus (Sso) and Methanothermobacter thermautotrophicus (Mth). Those domains consist of a structurally conserved truncated winged helix (WH) domain lacking the two typical 'wings' of canonical WH domains. A less conserved N-terminal extension links this WH module to the MCM AAA+ domain forming the ATPase center. In the Sso MCM this linker contains a short alpha-helical element. Using Sso MCM mutants, including chimeric constructs containing Mth C-terminal domain elements, we show that the ATPase and helicase activity of the Sso MCM is significantly modulated by the short alpha-helical linker element and by N-terminal residues of the first alpha-helix of the truncated WH module. Finally, based on our structural and functional data, we present a docking-derived model of the Sso MCM, which implies an allosteric control of the ATPase center by the C-terminal domain. Structure and regulatory role of the C-terminal winged helix domain of the archaeal minichromosome maintenance complex.,Wiedemann C, Szambowska A, Hafner S, Ohlenschlager O, Guhrs KH, Gorlach M Nucleic Acids Res. 2015 Mar 11;43(5):2958-67. doi: 10.1093/nar/gkv120. Epub 2015 , Feb 20. PMID:25712103[2] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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