title: The 1.8-Å crystal structure of the N-terminal domain of an archaeal MCM as a right-handed filament.
abstract: Mini-chromosome maintenance (MCM) proteins are the replicative helicase necessary for DNA replication in both eukarya and archaea. Most of archaea only have one MCM gene. Here, we report a 1.8-Å crystal structure of the N-terminal MCM from the archaeon Thermoplasma acidophilum (tapMCM). In the structure, the MCM N-terminus forms a right-handed filament that contains six subunits in each turn, with a diameter of 25Å of the central channel opening. The inner surface is highly positively charged, indicating DNA binding. This filament structure with six subunits per turn may also suggests a potential role for an open-ring structure for hexameric MCM and dynamic conformational changes in initiation and elongation stages of DNA replication.
authors.affiliation: Molecular and Computational Biology Program, Department of Biological Sciences, University of Southern California, Los Angeles, CA 90089, USA.
authors.forename: Yang
authors.initials: Y
authors.lastname: Fu
authors.affiliation: Molecular and Computational Biology Program, Department of Biological Sciences, University of Southern California, Los Angeles, CA 90089, USA.
authors.forename: Ian M
authors.initials: IM
authors.lastname: Slaymaker
authors.affiliation: Molecular and Computational Biology Program, Department of Biological Sciences, University of Southern California, Los Angeles, CA 90089, USA.
authors.forename: Junfeng
authors.initials: J
authors.lastname: Wang
authors.affiliation: Molecular and Computational Biology Program, Department of Biological Sciences, University of Southern California, Los Angeles, CA 90089, USA.
authors.forename: Ganggang
authors.initials: G
authors.lastname: Wang
authors.affiliation: Molecular and Computational Biology Program, Department of Biological Sciences, University of Southern California, Los Angeles, CA 90089, USA; Department of Chemistry, University of Southern California, Los Angeles, CA 90089, USA; Center of Excellence in NanoBiophysics, University of Southern California, Los Angeles, CA 90089, USA; Norris Comprehensive Cancer Center, University of Southern California, Los Angeles, CA 90089, USA. Electronic address: Xiaojiang.chen@usc.edu.
authors.forename: Xiaojiang S
authors.initials: XS
authors.lastname: Chen
mesh_terms: D001105:Archaea / Q000378:metabolism*; D019843:Archaeal Proteins / Q000378:metabolism; D004247:DNA / Q000737:chemistry / Q000378:metabolism; D004265:DNA Helicases / Q000378:metabolism; D004261:DNA Replication / Q000502:physiology; D004277:DNA, Single-Stranded / Q000737:chemistry / Q000378:metabolism; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D013822:Thermoplasma / Q000378:metabolism
chemical_list: D019843:Archaeal Proteins; D004277:DNA, Single-Stranded; D004247:DNA; D004265:DNA Helicases
keywords: DNA replication; MCM; crystal structure; helicase