Abstract
Phenotypes of secY and secA temperature-sensitive mutants at permissive (low) temperature have been examined. The secY24 mutant was found to be extremely susceptible to export inhibition by a basal-level synthesis of the MalE-LacZ 72-47 hybrid protein or to overproduction of a normal secretory protein such as maltose-binding protein or beta-lactamase. Comparison of this phenotype of secY24 with those of the secY100 and secA51 mutants under similar conditions suggested that MalE-LacZ protein and overproduced secretory protein do not nonspecifically enhance the partial secretion defect but act synergistically with secY24 to inhibit protein export.
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Selected References
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