|
|
||||||||
1 Departamento de Biotecnología, Instituto de Agroquímica y Tecnología de Alimentos, CSIC, Apdo. Correos 73, 46100 Burjassot, Spain
2 Microbiologie et Génétique Moléculaire, CNRS/INRA/INA-PG, UMR2585, 78850 Thiverval-Grignon, France
Correspondence
Gaspar Pérez-Martínez
gaspar.perez{at}iata.csic.es
Lactobacillus casei transports glucose preferentially by a mannose-class phosphoenolpyruvate : sugar phosphotransferase system (PTS). The genomic analysis of L. casei allowed the authors to find a gene cluster (manLMNO) encoding the IIAB (manL), IIC (manM) and IID (manN) proteins of a mannose-class PTS, and a putative 121 aa protein of unknown function (encoded by manO), homologues of which are also present in man clusters that encode glucose/mannose transporters in other Gram-positive bacteria. The L. casei man operon is constitutively expressed into a manLMNO messenger, but an additional manO transcript was also detected. Upstream of the man operon, two genes (upsR and upsA) were found which encode proteins resembling a transcriptional regulator and a membrane protein, respectively. Disruption of either upsR or upsA did not affect manLMNO transcription, and had no effect on glucose uptake. Cells carrying a manO deletion transported glucose at a rate similar to that of the wild-type strain. By contrast, a manM disruption resulted in cells unable to transport glucose by the PTS, thus confirming the functional role of the man genes. In addition, the manM mutant exhibited neither inducer exclusion of maltose nor glucose repression. This result confirms the need for glucose transport through the PTS to trigger these regulatory processes in L. casei.
The GenBank/EMBL/DDBJ accession number for the sequence reported in this paper is DQ011873.
This article has been cited by other articles:
![]() |
J. Thompson, N. Jakubovics, B. Abraham, S. Hess, and A. Pikis The sim Operon Facilitates the Transport and Metabolism of Sucrose Isomers in Lactobacillus casei ATCC 334 J. Bacteriol., May 1, 2008; 190(9): 3362 - 3373. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. Deutscher, C. Francke, and P. W. Postma How Phosphotransferase System-Related Protein Phosphorylation Regulates Carbohydrate Metabolism in Bacteria Microbiol. Mol. Biol. Rev., December 1, 2006; 70(4): 939 - 1031. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| INT J SYST EVOL MICROBIOL | MICROBIOLOGY | J GEN VIROL |
| J MED MICROBIOL | ALL SGM JOURNALS | |