Biomaterial Database

Interaction of single-strand binding protein and RecA protein at the single-stranded DNA site. 1983

S P Cohen, and J Resnick, and R Sussman

Escherichia coli single-strand binding protein (SSB), which participates in DNA replication, also plays a role in DNA repair and induction of SOS functions. We show that the formation of RecA-dATP-single-stranded DNA complexes is influenced by the presence of SSB. In equilibrium reactions with limiting bacteriophage fd DNA, the mutant SSB113 protein competes more effectively than SSB with RecA protein for sites on the DNA. This result can account for the inability of strain ssb113 to amplify RecA protein synthesis and induce lambda prophage. SSB fails to displace RecA protein completely, even at very high concentrations. Both proteins inhibit the dATPase activity of RecA protein in spite of a large proportion of RecA protein still complexed to single-stranded DNA. Analysis of the multiple RecA protein activities and how they respond to the presence of SSB suggests that they fall into two distinct classes. Those that are enhanced by SSB (proteolysis and strand assimilation) and those inhibited by SSB (NTPase, reannealing of complementary single-stranded DNA). We propose a two-state model of conformational change of RecA protein, affected by the number of available free bases in single-stranded DNA relative to the number of RecA monomers, that would explain the choice of mutually exclusive catalytic activities.

UI	MeSH Term	Description	Entries
D011938	Rec A Recombinases	A family of recombinases initially identified in BACTERIA. They catalyze the ATP-driven exchange of DNA strands in GENETIC RECOMBINATION. The product of the reaction consists of a duplex and a displaced single-stranded loop, which has the shape of the letter D and is therefore called a D-loop structure.	Rec A Protein,RecA Protein,Recombinases, Rec A
D002352	Carrier Proteins	Proteins that bind or transport specific substances in the blood, within the cell, or across cell membranes.	Binding Proteins,Carrier Protein,Transport Protein,Transport Proteins,Binding Protein,Protein, Carrier,Proteins, Carrier
D003838	Deoxyadenine Nucleotides	Adenine nucleotides which contain deoxyribose as the sugar moiety.	Deoxyadenosine Phosphates,Nucleotides, Deoxyadenine,Phosphates, Deoxyadenosine
D004260	DNA Repair	The removal of DNA LESIONS and/or restoration of intact DNA strands without BASE PAIR MISMATCHES, intrastrand or interstrand crosslinks, or discontinuities in the DNA sugar-phosphate backbones.	DNA Damage Response
D004277	DNA, Single-Stranded	A single chain of deoxyribonucleotides that occurs in some bacteria and viruses. It usually exists as a covalently closed circle.	Single-Stranded DNA,DNA, Single Stranded,Single Stranded DNA
D004926	Escherichia coli	A species of gram-negative, facultatively anaerobic, rod-shaped bacteria (GRAM-NEGATIVE FACULTATIVELY ANAEROBIC RODS) commonly found in the lower part of the intestine of warm-blooded animals. It is usually nonpathogenic, but some strains are known to produce DIARRHEA and pyogenic infections. Pathogenic strains (virotypes) are classified by their specific pathogenic mechanisms such as toxins (ENTEROTOXIGENIC ESCHERICHIA COLI), etc.	Alkalescens-Dispar Group,Bacillus coli,Bacterium coli,Bacterium coli commune,Diffusely Adherent Escherichia coli,E coli,EAggEC,Enteroaggregative Escherichia coli,Enterococcus coli,Diffusely Adherent E. coli,Enteroaggregative E. coli,Enteroinvasive E. coli,Enteroinvasive Escherichia coli
D001426	Bacterial Proteins	Proteins found in any species of bacterium.	Bacterial Gene Products,Bacterial Gene Proteins,Gene Products, Bacterial,Bacterial Gene Product,Bacterial Gene Protein,Bacterial Protein,Gene Product, Bacterial,Gene Protein, Bacterial,Gene Proteins, Bacterial,Protein, Bacterial,Proteins, Bacterial