title: Crystal structure of the N-terminal domain of Geobacillus kaustophilus HTA426 DnaD protein.
abstract: The DnaD is one of the primosomal proteins that are required for initiation and re-initiation of chromosomal DNA replication in Gram-positive bacteria. The DnaD protein is composed of two major structural domains: an N-terminal oligomerization domain and a C-terminal ssDNA binding domain. Here, we report the crystal structure of the N-terminal domain (aa 1-128) of DnaD (DnaDn) of Geobacillus kaustophilus HTA426 at 2.3A resolution. The structure of DnaDn reveals an extended winged-helix fold, a typical double-stranded DNA binding motif as winged-helix proteins. DnaDn formed tetramers in the crystalline state, but the results of gel filtration chromatography further indicated that this domain of DnaD was a stable dimer in solution. The structural analysis of DnaDn may suggest the binding sites for DNA and DnaB, and an assembly mechanism for Gram-positive bacterial DNA replication primosome.
authors.affiliation: Department of Biomedical Sciences, Chung Shan Medical University, No. 110, Sec. 1, Chien-Kuo N. Road, Taichung 402, Taiwan. cyhuang@csmu.edu.tw
authors.forename: Cheng-Yang
authors.initials: CY
authors.lastname: Huang
authors.forename: Yi-Wei
authors.initials: YW
authors.lastname: Chang
authors.forename: Wei-Ti
authors.initials: WT
authors.lastname: Chen
mesh_terms: D001406:Bacillaceae / Q000378:metabolism*; D001426:Bacterial Proteins / Q000737:chemistry*; D001665:Binding Sites; D018360:Crystallography, X-Ray; D004268:DNA-Binding Proteins / Q000737:chemistry*; D019281:Dimerization; D008958:Models, Molecular; D017434:Protein Structure, Tertiary
chemical_list: D001426:Bacterial Proteins; D004268:DNA-Binding Proteins