ISSN:
1617-4623
Keywords:
envCD operon
;
Nucleotide sequence
;
EnvC protein
;
Membrane localization
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Summary The chromosomal DNA insert in plasmid pJK131, which complements the phenotypic defects associated with a mutation in the envC gene of Escherichia coli strain PM61, was sequenced. The analysis of the nucleotide sequence revealed two open reading frames (ORFs) coding for the proteins EnvC (41281 daltons) and EnvD (104415 daltons). The envC gene product is synthesized as a pre-protein and, after cleavage of a signal peptide, the mature protein is incorporated into the cytoplasmic membrane. The detection of a common transcript for both ORFs indicated the existence of an envCD operon. Deletion analysis and the generation of frameshifts demonstrated that simultaneous expression of both genes is required to complement the defects in strain PM61. Overproduction of EnvC protein appears to be lethal to Escherichia coli. The envD gene, however, could be cloned and expressed at high levels under control of the tac promotor without deleterious effects on the host.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00290673
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