TY - JOUR
T1 - Conditionally lethal amber mutations in the leader peptidase gene of Escherichia coli.
AU - Inada, T.
AU - Court, D. L.
AU - Ito, K.
AU - Nakamura, Y.
PY - 1989/1
Y1 - 1989/1
N2 - 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.
AB - 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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U2 - 10.1128/jb.171.1.585-587.1989
DO - 10.1128/jb.171.1.585-587.1989
M3 - Article
C2 - 2644209
AN - SCOPUS:0024526131
VL - 171
SP - 585
EP - 587
JO - Journal of Bacteriology
JF - Journal of Bacteriology
SN - 0021-9193
IS - 1
ER -