Azide-resistant mutants of Escherichia coli alter the SecA protein, an azide-sensitive component of the protein export machinery.
Escherichia coli azi mutants, whose growth is resistant to millimolar concentrations of sodium azide, were among the earliest E. coli mutants isolated. Genetic complementation, mapping, and DNA sequence analysis now show that these mutations are alleles of the secA gene, which is essential for protein export across the E. coli plasma membrane. We have found that sodium azide is an extremely rapid and potent inhibitor of protein export in vivo and that azi mutants are more resistant to such inhibition. Furthermore, SecA-dependent in vitro protein translocation and ATPase activities are inhibited by sodium azide, and SecA protein prepared from an azi mutant strain is more resistant to such inhibition. These studies point to the utility of specific inhibitors of protein export, such as sodium azide, in facilitating the dissection of the function of individual components of the protein export machinery.
Oliver
D B
DB
Department of Microbiology, State University of New York, Stony Brook 11794.
Cabelli
R J
RJ
Dolan
K M
KM
Jarosik
G P
GP
D000251:Adenosine Triphosphatases / Q000235:genetics*; D001386:Azides / Q000494:pharmacology*; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism*; D002462:Cell Membrane / Q000378:metabolism; D002874:Chromosome Mapping; D004352:Drug Resistance, Microbial / Q000235:genetics; D004926:Escherichia coli / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism; D029968:Escherichia coli Proteins; D005798:Genes, Bacterial; D005816:Genetic Complementation Test; D026901:Membrane Transport Proteins; D009154:Mutation; D000069816:SEC Translocation Channels; D000081416:SecA Proteins; D019810:Sodium Azide
D001386:Azides; D001426:Bacterial Proteins; D029968:Escherichia coli Proteins; D026901:Membrane Transport Proteins; D000069816:SEC Translocation Channels; D019810:Sodium Azide; D000251:Adenosine Triphosphatases; D000081416:SecA Proteins