The Bifidobacterium longum NCIMB 702259 ^T ctr Gene Codes for a Novel Cholate Transporter

Abstract

Preexposure of Bifidobacterium longum NCIMB 702259T to cholate caused increased resistance to cholate, chloramphenicol, and erythromycin. The B. longum ctr gene, encoding a cholate efflux transporter, was transformed into the efflux-negative mutant Escherichia coli KAM3, conferring resistance to bile salts and other antimicrobial compounds and causing the efflux of [ 14 C]cholate.

Discovering Novel Bile Protection Systems in Bifidobacterium breve UCC2003 through Functional Genomics

“…Some of these are annotated as MDR transporters, reported to be involved in detoxification of a wide variety of structurally unrelated inhibitory substances (32). Homologs of some MDR transporters, such as Ctr and BetA, have previously been found to be involved in bile detoxification in other bifidobacteria (10,34).…”

“…In relation to bifidobacterial bile resistance systems, two bile efflux transporters from Bifidobacterium longum, BetA and Ctr, have been described previously, and their protective role against bile was demonstrated when expressed in Escherichia coli (10,34). Moreover, transcription of betA was shown to be bile inducible (10).…”

The Plastidic Bile Acid Transporter 5 Is Required for the Biosynthesis of Methionine-Derived Glucosinolates inArabidopsis thaliana

“…BLAST searches using the Arabidopsis BAT protein sequences revealed that Oryza sativa also possesses five different BAT proteins (Rzewuski and Sauter, 2002) and that a large number of ESTs encoding plant BAT proteins can be found throughout the plant kingdom and in a variety of bacteria (Figure 2; see Supplemental Data Set 1 online). Whereas the only bacterial putative BAT ortholog was recently identified as a cholate transporter named Ctr in Bifidobacterium longum (Price et al, 2006), the function(s) of the plant proteins remains to be elucidated. For a detailed analysis of the organ-and tissue-specific expression profile of the BAT5 gene, a translational fusion of the BAT5 promoter containing the first exon with the uidA (GUS) gene was analyzed for GUS activity in several transgenic Arabidopsis lines.…”

Bile salt hydrolase and antimicrobial activities of three bile resistant probiotics Lactobacillus plantarum strains isolated from Cameroonian artisanal fermented milk

“…Amongst those mechanisms are the bile efflux (17,18,19), counteracting H + accumulation by ATPase F0F1 pump (20), modification of plasma membrane composition (21)(22)(23) and bile salts deconjugation through the activity of bile-salt-hydrolases (BSHs) (24)(25)(26). The bile salts hydrolases produced by lactic acid bacteria are responsible for the deconjugation of bile salts with the formation of amino acid residues and deconjugated bile acids.…”