This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Reprints and Permissions Copyright Information Books from ASM Press MicrobeWorld Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Eident-Wilkinson, B Articles by Firshein, W Search for Related Content PubMed PubMed Citation Articles by Eident-Wilkinson, B Articles by Firshein, W

 Previous Article  |  Next Article 

J Bacteriol. 1992 January; 174(2): 477-485

research-article

Temporal expression of a membrane-associated protein putatively involved in repression of initiation of DNA replication in Bacillus subtilis.

B Eident-Wilkinson, L Mele, J Laffan and W Firshein

Department of Molecular Biology and Biochemistry, Wesleyan University, Middletown, Connecticut 06459.

ABSTRACT

A Bacillus subtilis membrane-associated protein that binds specifically to the origin region of DNA replication may act as an inhibitor of DNA replication (J. Laffan and W. Firshein, Proc. Natl. Acad. Sci. USA 85:7452-7456, 1988). This protein, originally estimated to be 64 kDa, had a slightly lower molecular size (57 kDa), as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis during these studies. The size difference may be due to processing that results in modification of the protein. The protein can be extracted from both cytosol and membrane fractions, and the amounts in these fractions vary during the developmental cycle of B. subtilis. A complex pattern of expression in which significant levels were detected in spores was revealed; levels decreased dramatically during germination and increased after the first round of DNA replication. The decrease during germination was due to protease activity, as demonstrated by the addition of protease inhibitors and radioactive-labeling chase experiments. During vegetative growth, the protein levels increased until stationary phase, after which there was another decrease during sporulation. The decrease during sporulation may be partially due to sequestering of the protein into forespores, since as the putative repressor protein decreased in the mother cell, it increased in the forespores. However, protease activity was also involved in the decrease in the mother cell. The changes in expression of this protein are consistent with its role as a repressor of initiation of DNA replication. Additional studies, including sequence analysis and further antibody analysis, show that this protein is not a subunit of the pyruvate dehydrogenase complex. This relationship had been a possibility based upon the results of others (H. Hemila, A. Pavla, L. Paulin, S. Arvidson, and I. Palva, J. Bacteriol. 172:5052-5063, 1990).

---

J Bacteriol. 1992 January; 174(2): 477-485

This article has been cited by other articles:

• Gao, H., Jiang, X., Pogliano, K., Aronson, A. I. (2002). The E1{beta} and E2 Subunits of the Bacillus subtilis Pyruvate Dehydrogenase Complex Are Involved in Regulation of Sporulation. J. Bacteriol. 184: 2780-2788 [Abstract] [Full Text]  
• Stein, A., Firshein, W. (2000). Probable Identification of a Membrane-Associated Repressor of Bacillus subtilis DNA Replication as the E2 Subunit of the Pyruvate Dehydrogenase Complex. J. Bacteriol. 182: 2119-2124 [Abstract] [Full Text]  
• Walter, T., Aronson, A. (1999). Specific Binding of the E2 Subunit of Pyruvate Dehydrogenase to the Upstream Region of Bacillus thuringiensis Protoxin Genes. J. Biol. Chem. 274: 7901-7906 [Abstract] [Full Text]