title: Structure of the Cdt1 C-terminal domain: conservation of the winged helix fold in replication licensing factors.
abstract: In eukaryotic replication licensing, Cdt1 plays a key role by recruiting the MCM2-7 complex onto the origin of chromosome. The C-terminal domain of mouse Cdt1 (mCdt1C), the most conserved region in Cdt1, is essential for licensing and directly interacts with the MCM2-7 complex. We have determined the structures of mCdt1CS (mCdt1C_small; residues 452 to 557) and mCdt1CL (mCdt1C_large; residues 420 to 557) using X-ray crystallography and solution NMR spectroscopy, respectively. While the N-terminal 31 residues of mCdt1CL form a flexible loop with a short helix near the middle, the rest of mCdt1C folds into a winged helix structure. Together with the middle domain of mouse Cdt1 (mCdt1M, residues 172-368), this study reveals that Cdt1 is formed with a tandem repeat of the winged helix domain. The winged helix fold is also conserved in other licensing factors including archaeal ORC and Cdc6, which supports an idea that these replication initiators may have evolved from a common ancestor. Based on the structure of mCdt1C, in conjunction with the biochemical analysis, we propose a binding site for the MCM complex within the mCdt1C.
authors.affiliation: The Magnetic Resonance Team, Korea Basic Science Institute, 804-1 Yangchung-Ri, Ochang, Chungbuk 363-883, South Korea.
authors.forename: Bulat I
authors.initials: BI
authors.lastname: Khayrutdinov
authors.forename: Won Jin
authors.initials: WJ
authors.lastname: Bae
authors.forename: Young Mi
authors.initials: YM
authors.lastname: Yun
authors.forename: Jie Hye
authors.initials: JH
authors.lastname: Lee
authors.forename: Takashi
authors.initials: T
authors.lastname: Tsuyama
authors.forename: Jung Joo
authors.initials: JJ
authors.lastname: Kim
authors.forename: Eunha
authors.initials: E
authors.lastname: Hwang
authors.forename: Kyoung-Seok
authors.initials: KS
authors.lastname: Ryu
authors.forename: Hae-Kap
authors.initials: HK
authors.lastname: Cheong
authors.forename: Chaejoon
authors.initials: C
authors.lastname: Cheong
authors.forename: Jung-Soon
authors.initials: JS
authors.lastname: Ko
authors.forename: Takemi
authors.initials: T
authors.lastname: Enomoto
authors.forename: P Andrew
authors.initials: PA
authors.lastname: Karplus
authors.forename: Peter
authors.initials: P
authors.lastname: Güntert
authors.forename: Shusuke
authors.initials: S
authors.lastname: Tada
authors.forename: Young Ho
authors.initials: YH
authors.lastname: Jeon
authors.forename: Yunje
authors.initials: Y
authors.lastname: Cho
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites / Q000235:genetics*; D018797:Cell Cycle Proteins / Q000737:chemistry* / Q000235:genetics; D017124:Conserved Sequence / Q000235:genetics*; D004268:DNA-Binding Proteins / Q000737:chemistry* / Q000235:genetics; D051379:Mice; D008969:Molecular Sequence Data; D009154:Mutation; D019906:Nuclear Magnetic Resonance, Biomolecular; D009687:Nuclear Proteins / Q000737:chemistry / Q000235:genetics; D017434:Protein Structure, Tertiary / Q000235:genetics*; D016415:Sequence Alignment
chemical_list: D018797:Cell Cycle Proteins; D004268:DNA-Binding Proteins; D009687:Nuclear Proteins; C498645:Ris2 protein, mouse