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Iterative Optimization of DNA Duplexes for Crystallization of SeqA-DNA Complexes
Published on: November 1, 2012
Crystal structure of the N-terminal domain of Geobacillus kaustophilus HTA426 DnaD protein
Cheng-Yang Huang1, Yi-Wei Chang, Wei-Ti Chen
1Department of Biomedical Sciences, Chung Shan Medical University, No. 110, Sec. 1, Chien-Kuo N. Road, Taichung 402, Taiwan. cyhuang@csmu.edu.tw
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.
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