Medium-dependent regulation of proteinase gene expression in Lactococcus lactis: control of transcription initiation by specific dipeptides
Transcriptional gene fusions with the Escherichia coli beta-glucuronidase gene (gusA) were used to study the medium- and growth dependent expression of the divergently transcribed genes involved in proteinase production (prtP and prtM) of Lactococcus lactis SK11. The results show that both the prtP...
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Published in | Journal of Bacteriology Vol. 177; no. 11; pp. 2982 - 2989 |
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Main Authors | , , , , , |
Format | Journal Article |
Language | English |
Published |
United States
American Society for Microbiology
01.06.1995
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Subjects | |
Online Access | Get full text |
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Summary: | Transcriptional gene fusions with the Escherichia coli beta-glucuronidase gene (gusA) were used to study the medium- and growth dependent expression of the divergently transcribed genes involved in proteinase production (prtP and prtM) of Lactococcus lactis SK11. The results show that both the prtP and prtM genes are controlled at the transcriptional level by the peptide content of the medium and, to a lesser extent, by the growth rate. A more than 10-fold regulation in beta-glucuronidase activity was observed for both prtP and prtM promoters in batch and continuous cultures. The level of expression of the prtP and prtM promoters was high in whey permeate medium with relatively low concentrations of peptides, whereas at increased concentrations the expression of the promoters was repressed. The lowest level of expression was observed in peptide- and amino acid-rich laboratory media, such as glucose M17 and MRS. The addition of specific dipeptides, such as leucylproline and prolylleucine, to the growth medium negatively affected the expression of the prtP-gusA fusions. The repression by dipeptides was not observed in mutants defective in the uptake of di-tripeptides, indicating that the internal concentration of dipeptides or derivatives is important in the regulation of proteinase production |
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Bibliography: | 9550224 Q02 ObjectType-Article-2 SourceType-Scholarly Journals-1 ObjectType-Feature-1 content type line 23 ObjectType-Article-1 ObjectType-Feature-2 |
ISSN: | 0021-9193 1098-5530 1067-8832 |
DOI: | 10.1128/jb.177.11.2982-2989.1995 |