Molecular analysis and nucleotide sequence of the envCD operon of Escherichia coli.
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 (41,281 daltons) and EnvD (104,415 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 promoter without deleterious effects on the host.
Klein
J R
JR
Abteilung Mikrobiologie, Universität Kaiserslautern, FRG.
Henrich
B
B
Plapp
R
R
D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D001483:Base Sequence; D015152:Blotting, Northern; D002352:Carrier Proteins; D002462:Cell Membrane / Q000378:metabolism; D004269:DNA, Bacterial / Q000235:genetics; D004591:Electrophoresis, Polyacrylamide Gel; D004926:Escherichia coli / Q000235:genetics*; D029968:Escherichia coli Proteins; D016368:Frameshift Mutation; D005798:Genes, Bacterial; D008565:Membrane Proteins / Q000235:genetics* / Q000378:metabolism; D008969:Molecular Sequence Data; D027425:ATP-Binding Cassette, Sub-Family C Proteins; D016366:Open Reading Frames; D009876:Operon; D010957:Plasmids; D011401:Promoter Regions, Genetic; D012329:RNA, Bacterial / Q000235:genetics; D015183:Restriction Mapping; D014158:Transcription, Genetic
D001426:Bacterial Proteins; D002352:Carrier Proteins; D004269:DNA, Bacterial; D029968:Escherichia coli Proteins; D008565:Membrane Proteins; D027425:ATP-Binding Cassette, Sub-Family C Proteins; D012329:RNA, Bacterial; C083496:AcrB protein, E coli; C071960:acrF protein, E coli