Structure and expression of gene vfr in Pseudomonas chlororaphis 449

Gene vfr of Pseudomonas chlororaphis 449 previously described only in Pseudomonas aeruginosa was identified, cloned, and sequenced; its localization in the chromosome was determined. Amino acid sequence of the protein encoded by gene vfr in P. chlororaphis 449 was shown to have a 83% identity with the Vfr protein of P. aeruginosa PAO1 and a 63% identity with the CRP protein of Escherichia coli. Amino acid residues that ensure the most important structural properties of the CRP protein, i.e., its binding to cAMP, RNA polymerase, and DNA, were identical or highly conserved in Vfr proteins of P. aeruginosa and P. chlororaphis 449. The cloned vfr gene of P. chlororaphis 449 was complemented partially the mutation at gene crp in cells of E. coli AM306 enhancing ten times synthesis of β-galactosidase dependent on the CRP protein. Unlike P. aeruginosa, the Vfr protein in cells of P. chlororaphis 449 does not participate in the regulation of synthesis of N-acyl-homoserine lactones.