The Enterococcus faecalis gene encoding the novel general stress protein Gsp62.
The Enterococcus faecalis general stress protein Gsp62 was purified using two-dimensional gel electrophoresis and its 25 N-terminal amino acid sequence determined. Analysis of the corresponding gene revealed that the gsp62 product is a 172 aa protein. Transcriptional analysis of gsp62 gave evidence for a monocistronic mRNA, the synthesis of which was induced at the onset of stationary phase and in response to heat shock, acid pH, detergents (i.e. SDS or bile salts), ethanol, tert-butyl hydroperoxide, sodium chloride and, to a lesser extent, hydrogen peroxide. 5' rapid amplification of cDNA ends by PCR experiments showed that gsp62 transcription initiates 30 nt upstream of the ATG start codon. Although gsp62 expression was induced in response to various stresses, its disruption had no significant effect on the cell survival after each individual stress. Two-dimensional protein gels from wild-type and mutant cells revealed no pleiotropic effect of the mutation on protein synthesis. Transcriptional fusions with the lacL lacM beta-galactosidase genes showed that an inverted repeat located upstream of the promoter is required for transcriptional induction by environmental stresses but not by entrance into stationary phase. Two distinct mechanisms responding to different signals are thus involved in gsp62 induction.
Rincé
Alain
A
Laboratoire de Microbiologie de l'Environnement, IRBA, Université de Caen, 14032 Caen Cedex, France1.
Uguen
Marilyne
M
Laboratoire de Biologie et Chimie Moléculaires, EA 2594, Université de Bretagne Sud, 56000 Vannes, France2.
Le Breton
Yoann
Y
Laboratoire de Microbiologie de l'Environnement, IRBA, Université de Caen, 14032 Caen Cedex, France1.
Giard
Jean-Christophe
JC
Laboratoire de Microbiologie de l'Environnement, IRBA, Université de Caen, 14032 Caen Cedex, France1.
Flahaut
Sigrid
S
Laboratoire de Microbiologie de l'Environnement, IRBA, Université de Caen, 14032 Caen Cedex, France1.
Dufour
Alain
A
Laboratoire de Biologie et Chimie Moléculaires, EA 2594, Université de Bretagne Sud, 56000 Vannes, France2.
Auffray
Yanick
Y
Laboratoire de Microbiologie de l'Environnement, IRBA, Université de Caen, 14032 Caen Cedex, France1.
D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism; D001483:Base Sequence; D013293:Enterococcus faecalis / Q000235:genetics* / Q000378:metabolism / Q000502:physiology*; D017353:Gene Deletion; D015964:Gene Expression Regulation, Bacterial; D006360:Heat-Shock Proteins / Q000737:chemistry / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic; D017422:Sequence Analysis, DNA; D014158:Transcription, Genetic; D001616:beta-Galactosidase / Q000378:metabolism
D001426:Bacterial Proteins; D006360:Heat-Shock Proteins; D001616:beta-Galactosidase