Molecular analysis of the glucose-specific phosphoenolpyruvate : sugar phosphotransferase system from Lactobacillus casei and its links with the control of sugar metabolism

• Published in: Microbiology (Society for General Microbiology) Vol. 152; no. 1; pp. 95 - 104
• Main Authors: Yebra, Maria J, Monedero, Vicente, Zuniga, Manuel, Deutscher, Josef, Perez-Martinez, Gaspar
• Format: Journal Article
• Language: English
• Published: Reading Soc General Microbiol 01-01-2006; Society for General Microbiology
• Subjects: Amino Acid Sequence; Bacterial Proteins - genetics; Bacterial Proteins - metabolism; Bacteriology; Base Sequence; Biological and medical sciences; Biological Transport; Fundamental and applied biological sciences. Psychology; Genetics; Lactobacillus casei; Lactobacillus casei - genetics; Lactobacillus casei - metabolism; Metabolism. Enzymes; Microbiology; Molecular Sequence Data; Multigene Family; Operon; Phosphoenolpyruvate - metabolism; Phosphoenolpyruvate Sugar Phosphotransferase System - genetics; Phosphoenolpyruvate Sugar Phosphotransferase System - metabolism; Lactic acid bacteria; Lactobacillus casei; Enzyme; Escherichia coli; Mannose; Glucose; Metabolism; Northern blotting; Isomerases; Enzymatic activity; Intramolecular transferases; Bacteria; Lactobacillaceae; Phosphotransferases; Reverse transcription polymerase chain reaction; Enterobacteriaceae
• ISSN: 1350-0872; 1465-2080
• DOI: 10.1099/mic.0.28293-0

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 .
Abbreviations: CCR, carbon catabolite repression; 2-DG, 2-deoxyglucose; LAB, lactic acid bacteria; PTS, phosphoenolpyruvate : sugar phosphotransferase system; RACE, rapid amplification of cDNA ends
The GenBank/EMBL/DDBJ accession number for the sequence reported in this paper is DQ011873 .