Structural highlights
Function
MCM_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 PubMed
The 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
- ↑ Carpentieri F, De Felice M, De Falco M, Rossi M, Pisani FM. Physical and functional interaction between the mini-chromosome maintenance-like DNA helicase and the single-stranded DNA binding protein from the crenarchaeon Sulfolobus solfataricus. J Biol Chem. 2002 Apr 5;277(14):12118-27. Epub 2002 Jan 30. PMID:11821426 doi:10.1074/jbc.M200091200
- ↑ Wiedemann C, Szambowska A, Hafner S, Ohlenschlager O, Guhrs KH, Gorlach M. Structure and regulatory role of the C-terminal winged helix domain of the archaeal minichromosome maintenance complex. Nucleic Acids Res. 2015 Mar 11;43(5):2958-67. doi: 10.1093/nar/gkv120. Epub 2015 , Feb 20. PMID:25712103 doi:http://dx.doi.org/10.1093/nar/gkv120
