Purification and preliminary characterization of the Escherichia coli K-12 recF protein.

摘要: Abstract The recF gene of Escherichia coli is known to encode an Mr-40,000 protein that involved in DNA recombinationa nd postreplication repair. To characterize the role product these processes, was cloned downstream a tac promoter facilitate overproduction product. The RecF overproduced and purified apparent homogeneity. N-terminal sequence analysis demonstrated had predicted from gene, except Met not present. bound single-stranded oligonucleotides filter binding gel filtration assays. Maximal required 2 3 min incubation at 37 degrees C; reaction pH optimum 7.0, did require divalent cations, inhibited by NaCl concentrations greater than 250 mM. Kd 59-base oligonucleotide on order 1.3 X 10(-7) M, show cooperativity. Experiments measuring various substrates competition experiments with different molecules binds preferentially single-stranded, linear molecules.