Structural Studies of Single-Stranded DNA Binding Protein from Helicobacter pylori

• Main Authors: Kun-Wei Chan, 詹坤衛
• Other Authors: Yuh-Ju Sun
• Format: Others
• Language: zh-TW
• Published: 2007
• Online Access: http://ndltd.ncl.edu.tw/handle/94826272919650941118

碩士 === 國立清華大學 === 生物資訊與結構生物研究所 === 95 === Abstract Single-stranded DNA binding protein (SSB) plays an important role in DNA metabolism, such as DNA replication, repair and recombination. The N-terminal domain of SSB forms an oligonucleotides/oligosaccharides binding (OB) fold, which function as single-stranded DNA (ssDNA) binding domain. The C-terminal conserved tail is supposed to participate in the protein-protein interaction. The crystal structure of C-terminal truncated SSB from Helicobacter pylori (residues 1-134, HpSSB134) bound to two dT(pT)34 [HpSSB134-dT(pT)34] was determined by molecular replacement method at 2.3 Å. The ssDNA wraps around four subunits of HpSSB134 by the electrostatic and hydrophobic stacking interactions. Four aromatic residues, Phe37, Phe50, Phe56 and Trp84, interact with the base of ssDNA by stacking arrangement. Meanwhile, four basic residues, Arg10, Arg36, Arg54 and Arg94, on the surface of HpSSB134 form a significant electrostatic path corresponding to the ssDNA binding.