Role of the general stress response during strong overexpression of a heterologous gene in Escherichia coli.
Appl Microbiol Biotechnol
; 58(3): 330-7, 2002 Mar.
Article
in En
| MEDLINE
| ID: mdl-11935184
ABSTRACT
The strong overexpression of heterologous genes in Escherichia coli often leads to inhibition of cell growth, ribosome destruction, loss of culturability, and induction of stress responses, such as a heat shock-like response. Here we demonstrate that the general stress response, which is connected to the stress response regulator sigmas (sigma38, rpoS gene product), is suppressed during strong overproduction of a heterologous alpha-glucosidase. The mRNA levels of the rpoS and osmY stress genes drastically decrease after induction of the strong overexpression system. It is shown that an rpoS mutation causes a significant loss of cell viability after induction of the expression system. Furthermore, it is demonstrated that an E. coli c/pP mutant, which could be suggested to improve heterologous protein production, is not a good production host if a tac-promoter is used to control the expression of the recombinant gene. Data from this study suggest that the overexpression of the alpha-glucosidase was greatly decreased by sigma factor competition in the clpP mutant, due to the increased sigmas level in this mutant background.
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Collection:
01-internacional
Database:
MEDLINE
Main subject:
Gene Expression Regulation, Bacterial
/
Escherichia coli Proteins
/
Escherichia coli
Language:
En
Journal:
Appl Microbiol Biotechnol
Year:
2002
Document type:
Article
Affiliation country:
Germany