کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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2186675 | 1096071 | 2009 | 12 صفحه PDF | دانلود رایگان |
Single-stranded DNA (ssDNA)-binding protein (SSB) plays an important role in DNA replication, recombination, and repair. SSB consists of an N-terminal ssDNA-binding domain with an oligonucleotide/oligosaccharide binding fold and a flexible C-terminal tail involved in protein–protein interactions. SSB from Helicobacter pylori (HpSSB) was isolated, and the ssDNA-binding characteristics of HpSSB were analyzed by fluorescence titration and electrophoretic mobility shift assay. Tryptophan fluorescence quenching was measured as 61%, and the calculated cooperative affinity was 5.4 × 107 M− 1 with an ssDNA-binding length of 25–30 nt. The crystal structure of the C-terminally truncated protein (HpSSBc) in complex with 35-mer ssDNA [HpSSBc–(dT)35] was determined at a resolution of 2.3 Å. The HpSSBc monomer folds as an oligonucleotide/oligosaccharide binding fold with a Y-shaped conformation. The ssDNA wrapped around the HpSSBc tetramer through a continuous binding path comprising five essential aromatic residues and a positively charged surface formed by numerous basic residues.
Journal: Journal of Molecular Biology - Volume 388, Issue 3, 8 May 2009, Pages 508–519