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. 1989 Jan;171(1):585–587. doi: 10.1128/jb.171.1.585-587.1989

Conditionally lethal amber mutations in the leader peptidase gene of Escherichia coli.

T Inada 1, D L Court 1, K Ito 1, Y Nakamura 1
PMCID: PMC209628  PMID: 2644209

Abstract

The lep gene of Escherichia coli encodes the leader peptidase which cleaves amino-terminal leader sequences of secreted proteins. To facilitate the study of structure-function relationships of the leader peptidase, 22 amber mutations in lep were isolated by localized mutagenesis. These amber mutants grew at 32 degrees C but not at 42 degrees C in the presence of a temperature-sensitive amber suppressor. Most of them were lethal under sup0 conditions. However, one amber mutant, the lep-9 mutant, exhibited temperature-sensitive growth in the sup0 strain, indicating that the amber fragment is active at 32 degrees C but not at 42 degrees C. Protein precursors of the maltose-binding protein and OmpA accumulate strikingly in the lep-9 mutant.

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Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Ahnn J., March P. E., Takiff H. E., Inouye M. A GTP-binding protein of Escherichia coli has homology to yeast RAS proteins. Proc Natl Acad Sci U S A. 1986 Dec;83(23):8849–8853. doi: 10.1073/pnas.83.23.8849. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. Dalbey R. E., Wickner W. Leader peptidase catalyzes the release of exported proteins from the outer surface of the Escherichia coli plasma membrane. J Biol Chem. 1985 Dec 15;260(29):15925–15931. [PubMed] [Google Scholar]
  3. Dalbey R. E., Wickner W. The role of the polar, carboxyl-terminal domain of Escherichia coli leader peptidase in its translocation across the plasma membrane. J Biol Chem. 1986 Oct 15;261(29):13844–13849. [PubMed] [Google Scholar]
  4. Date T. Demonstration by a novel genetic technique that leader peptidase is an essential enzyme of Escherichia coli. J Bacteriol. 1983 Apr;154(1):76–83. doi: 10.1128/jb.154.1.76-83.1983. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. Date T., Wickner W. Isolation of the Escherichia coli leader peptidase gene and effects of leader peptidase overproduction in vivo. Proc Natl Acad Sci U S A. 1981 Oct;78(10):6106–6110. doi: 10.1073/pnas.78.10.6106. [DOI] [PMC free article] [PubMed] [Google Scholar]
  6. Ito K., Bassford P. J., Jr, Beckwith J. Protein localization in E. coli: is there a common step in the secretion of periplasmic and outer-membrane proteins? Cell. 1981 Jun;24(3):707–717. doi: 10.1016/0092-8674(81)90097-0. [DOI] [PubMed] [Google Scholar]
  7. March P. E., Inouye M. Characterization of the lep operon of Escherichia coli. Identification of the promoter and the gene upstream of the signal peptidase I gene. J Biol Chem. 1985 Jun 25;260(12):7206–7213. [PubMed] [Google Scholar]
  8. Nakamura Y., Uchida H. Isolation of conditionally lethal amber mutations affecting synthesis of the nusA protein of Escherichia coli. Mol Gen Genet. 1983;190(2):196–203. doi: 10.1007/BF00330640. [DOI] [PubMed] [Google Scholar]
  9. Osawa T., Yura T. Amber mutations in the structural gene for RNA polymerase sigma factor of Escherichia coli. Mol Gen Genet. 1980;180(2):293–300. doi: 10.1007/BF00425841. [DOI] [PubMed] [Google Scholar]
  10. Shimura Y., Ozeki H. Genetic study on transfer RNA. Adv Biophys. 1973;4:191–226. [PubMed] [Google Scholar]
  11. Silver P., Wickner W. Genetic mapping of the Escherichia coli leader (signal) peptidase gene (lep): a new approach for determining the map position of a cloned gene. J Bacteriol. 1983 May;154(2):569–572. doi: 10.1128/jb.154.2.569-572.1983. [DOI] [PMC free article] [PubMed] [Google Scholar]
  12. VOGEL H. J., BONNER D. M. Acetylornithinase of Escherichia coli: partial purification and some properties. J Biol Chem. 1956 Jan;218(1):97–106. [PubMed] [Google Scholar]
  13. Wickner W. Assembly of proteins into membranes. Science. 1980 Nov 21;210(4472):861–868. doi: 10.1126/science.7001628. [DOI] [PubMed] [Google Scholar]
  14. Wolfe P. B., Silver P., Wickner W. The isolation of homogeneous leader peptidase from a strain of Escherichia coli which overproduces the enzyme. J Biol Chem. 1982 Jul 10;257(13):7898–7902. [PubMed] [Google Scholar]
  15. Wolfe P. B., Wickner W., Goodman J. M. Sequence of the leader peptidase gene of Escherichia coli and the orientation of leader peptidase in the bacterial envelope. J Biol Chem. 1983 Oct 10;258(19):12073–12080. [PubMed] [Google Scholar]
  16. Zwizinski C., Wickner W. Purification and characterization of leader (signal) peptidase from Escherichia coli. J Biol Chem. 1980 Aug 25;255(16):7973–7977. [PubMed] [Google Scholar]
  17. von Heijne G., Wickner W., Dalbey R. E. The cytoplasmic domain of Escherichia coli leader peptidase is a "translocation poison" sequence. Proc Natl Acad Sci U S A. 1988 May;85(10):3363–3366. doi: 10.1073/pnas.85.10.3363. [DOI] [PMC free article] [PubMed] [Google Scholar]

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