title: Comparative Genomic Analysis of Two-Component Signal Transduction Systems in Probiotic Lactobacillus casei.
abstract: Lactobacillus casei has traditionally been recognized as a probiotic, thus needing to survive the industrial production processes and transit through the gastrointestinal tract before providing benefit to human health. The two-component signal transduction system (TCS) plays important roles in sensing and reacting to environmental changes, which consists of a histidine kinase (HK) and a response regulator (RR). In this study we identified HKs and RRs of six sequenced L. casei strains. Ortholog analysis revealed 15 TCS clusters (HK-RR pairs), one orphan HKs and three orphan RRs, of which 12 TCS clusters were common to all six strains, three were absent in one strain. Further classification of the predicted HKs and RRs revealed interesting aspects of their putative functions. Some TCS clusters are involved with the response under the stress of the bile salts, acid, or oxidative, which contribute to survive the difficult journey through the human gastrointestinal tract. Computational predictions of 15 TCSs were verified by PCR experiments. This genomic level study of TCSs should provide valuable insights into the conservation and divergence of TCS proteins in the L. casei strains.
authors.affiliation: State Key Laboratory of Dairy Biotechnology, Bright Dairy & Food Co. Ltd, Shanghai, 200436 People's Republic of China ; Faculty of Resource and Environmental Engineering, Jiangxi University of Science and Technology, No. 86, Hongqi Ave., Ganzhou, 341000 Jiangxi People's Republic of China.
authors.forename: Shuijing
authors.initials: S
authors.lastname: Yu
authors.affiliation: Faculty of Resource and Environmental Engineering, Jiangxi University of Science and Technology, No. 86, Hongqi Ave., Ganzhou, 341000 Jiangxi People's Republic of China.
authors.forename: Yanping
authors.initials: Y
authors.lastname: Peng
authors.affiliation: State Key Laboratory of Dairy Biotechnology, Bright Dairy & Food Co. Ltd, Shanghai, 200436 People's Republic of China.
authors.forename: Wanyi
authors.initials: W
authors.lastname: Chen
authors.affiliation: Faculty of Resource and Environmental Engineering, Jiangxi University of Science and Technology, No. 86, Hongqi Ave., Ganzhou, 341000 Jiangxi People's Republic of China.
authors.forename: Yangwu
authors.initials: Y
authors.lastname: Deng
authors.affiliation: Faculty of Resource and Environmental Engineering, Jiangxi University of Science and Technology, No. 86, Hongqi Ave., Ganzhou, 341000 Jiangxi People's Republic of China.
authors.forename: Yanhua
authors.initials: Y
authors.lastname: Guo
keywords: Comparative genomics; Lactobacillus casei; Probiotic; Two-component signal transduction system