Molecular analysis of the recF gene of Escherichia coli.

Abstract

The nucleotide sequence of a 1.325-kilobase reigon of wild-type E. coli containing a functional recF gene and 6 transposon Tn3 mutations that inactivate recF was analyzed. The analysis shows a potentially translatable reading frame of 1071 nucleotides, which is interrupted by all 6 insertions. A protein of 40.5 kilodaltons (kd) would result from translation of the open reading frame, and a radioactive band of protein of an apparent MW of .apprx. 40 kd was seen by the maxicell method using a recF+ plasmid. Putative truncated peptides were seen when 2 recf::Tn3 mutant plasmids were used. Differential expression of dnaN and recF from a common promoter was noted. recF332::Tn3 was transferred to the chromosome where, in hemizygous condition, it produced UV sensitivity indistiguishable from that produced by 2 presumed recF point mutations.