This family consists of several fatty acid cis/trans isomerase proteins which appear to be found exclusively in bacteria of the orders Vibrionales and Pseudomonadales. Cis/trans isomerase (CTI) catalyses the cis-trans isomerisation of esterified unsaturated fatty acids in phospholipids, mainly palmitoleic acid (C16:1) and cis-vaccenic acid C(18:1), in response to toxic organic solvents, heat and osmotic stress, and heavy metals. The CTI protein is located in the periplasm and has been shown to be involved in solvent tolerance in Pseudomonas strains [1,2,3].

1: Involvement of the cis/trans isomerase Cti in solvent resistance of Pseudomonas putida DOT-T1E. Junker F, Ramos JL; J Bacteriol 1999;181:5693-5700. PMID:10482510

2: cis-trans isomerization of unsaturated fatty acids: cloning and sequencing of the cti gene from Pseudomonas putida P8. Holtwick R, Meinhardt F, Keweloh H; Appl Environ Microbiol 1997;63:4292-4297. PMID:9361416

3: Immediate response mechanisms of Gram-negative solvent-tolerant bacteria to cope with environmental stress: cis-trans isomerization of unsaturated fatty acids and outer membrane vesicle secretion. Eberlein C, Baumgarten T, Starke S, Heipieper HJ; Appl Microbiol Biotechnol. 2018;102:2583-2593. PMID:29450619