The Rapid Degradation of Mutant Sec A Protein in theBacillus subtilis secA341(ts) Mutant Causes a Protein Translocation Defect in the Cell
- 1 January 1994
- journal article
- Published by Taylor & Francis in Bioscience, Biotechnology, and Biochemistry
- Vol. 58 (10) , 1845-1850
- https://doi.org/10.1271/bbb.58.1845
Abstract
To study the function of SecA protein and the protein translocation system of Bacillus subtilis, wild-type and mutant SecA proteins were characterized in vivo and in vitro. SecA protein was abundant in a wild-type strain (168) and existed in a stable homodimer. In contrast to this, SecA341 (ts) protein having an amino acid replacement from proline to leucine at residue 431 was undetectable by immunoblotting in the cell lysate of a secA341 mutant (TB301) at the nonpermissive temperature, 42 degrees C. Pulse-chase studies using 35S-methionine showed that newly synthesized SecA protein was rapidly degraded in the mutant at 42 degrees C. Purified SecA341 protein was more sensitive to trypsin and subtilisin than purified wild-type SecA protein in the presence of ATP. These results indicate that the secA341 mutation causes the rapid degradation of mutant SecA protein and a concomitant protein translocation defect in the cell.Keywords
This publication has 1 reference indexed in Scilit:
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