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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.

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