cis-trans isomerization of unsaturated fatty acids: Cloning and sequencing of the cti gene from Pseudomonas putida P8

Transposon mutants of Pseudomonas putida P8 were generated by applying a mini-Tn5 mutagenesis system, The mutants obtained were checked for their ability to tolerate increased temperatures and elevated phenol concentrations, Approximately 5,800 transposon mutants were used to generate a pool of 600 temperature-sensitive strains; one of these strains was identified as being damaged in its ability to perform cis-trans isomerization of fatty acids, A gene library of P. putida P8 was constructed and screened by using as a probe sequences immediately adjacent to the mini-Tn5 insertion, A DNA fragment that complemented the mutation was isolated and cloned. The corresponding gene, termed cti, is located close to the methionine synthase locus (metH) in P, putida P8, A cti-carrying fragment integrated into a plasmid also conferred the ability for cis-trans isomerization to Escherichia coli; the cti gene was completely sequenced, and the amino acid sequence was deduced.