A single residue determines the cooperative binding property of a primosomal DNA replication protein, PriB, to single-stranded DNA.
PriB is a primosomal protein required for re-initiation of replication in bacteria. We characterized and compared the DNA-binding properties of PriB from Salmonella enterica serovar Typhimurium LT2 (StPriB) and Escherichia coli (EcPriB). Only one residue of EcPriB, V6, was different in StPriB (replaced by A6). Previous structural information revealed that this residue is located on the putative dimer-dimer interface of PriB and is not involved in single-stranded DNA (ssDNA) binding. The cooperative binding mechanism of StPriB to DNA is, however, very different from that of EcPriB. Unlike EcPriB, which forms a single complex with ssDNAs of various lengths, StPriB forms two or more distinct complexes. Based on these results, as well as information on structure, binding modes for forming a stable complex of PriB with ssDNA of 25 nucleotides (nt), (EcPriB)25, and (StPriB)25 are proposed.
Department of Biomedical Sciences, Chung Shan Medical University and Department of Medical Research, Chung Shan Medical University Hospital, Taichung City, Taiwan.
Yen-Hua
YH
Huang
Hsin-Hsien
HH
Lin
Cheng-Yang
CY
Huang
D000409:Alanine / Q000737:chemistry / Q000235:genetics; D001665:Binding Sites; D018360:Crystallography, X-Ray; D004261:DNA Replication; D004277:DNA, Single-Stranded / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D004926:Escherichia coli / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D029968:Escherichia coli Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D008958:Models, Molecular; D011485:Protein Binding; D020033:Protein Isoforms / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D055503:Protein Multimerization; D012486:Salmonella typhimurium / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D014633:Valine / Q000737:chemistry / Q000235:genetics
D004277:DNA, Single-Stranded; D004268:DNA-Binding Proteins; D029968:Escherichia coli Proteins; C086004:PriB protein, E coli; D020033:Protein Isoforms; D014633:Valine; D000409:Alanine