Previous Article | Next Article ![]()
J. Bacteriol., Jun 1996, 3457-3461, Vol 178, No. 12
JN Qu, SI Makino, H Adachi, Y Koyama, Y Akiyama, K Ito, T Tomoyasu, T Ogura and H Matsuzawa
Escherichia coli tolZ mutants are tolerant to colicins E2, E3, D, Ia, and
Ib (Tol-), can grow on glucose but not on succinate or other nonfermentable
carbon sources (Nfc-), and show temperature-sensitive growth (Ts). A 1.8-kb
DNA fragment that complemented the tolZ mutation was cloned. The DNA
fragment was sequenced, and one open reading frame was found. This frame
was identical to a part of the E. coli FtsH protein, an ATP-dependent
metalloprotease that binds to the cytoplasmic membrane. The tolZ gene was
located at 69 min on the E. coli genetic map, and the mutation was
complemented by a plasmid carrying the ftsH gene, indicating that the tolZ
gene is identical to the ftsH gene. The mutated tolZ21 gene was also cloned
and sequenced and was found to have a single base change that caused an
amino acid alteration of His-418 to Tyr in the FtsH protein. The tolZ21
mutant showed Hfl- (high frequency of lysogenization) and Std- (stop
transfer-defective) pheno-types, both of which are due to a mutation in the
ftsH (hflB) gene. However, the ftsH1, ftsH101, and hflB29 mutants did not
show Tol- and Nfc phenotypes. The tolZ21 mutant was found to have a
suppressor mutation, named sfhC, which allowed cells to survive. The sfhC
mutation alone caused no Tol-, Nfc-, Ts, or Hfl- phenotypes in the tolZ21
mutant.
Copyright © 1996, American Society for Microbiology
The tolZ gene of Escherichia coli is identified as the ftsH gene
Department of Biotechnology, University of Tokyo, Japan.
This article has been cited by other articles:
Copyright © 2009 by the American Society for Microbiology. For an alternate route to Journals.ASM.org, visit: http://intl-journals.asm.org | More Info»