Molecular and General Genetics MGG

, Volume 229, Issue 2, pp 189–196

Catabolite repression of the operon for xylose utilization from Bacillus subtilis W23 is mediated at the level of transcription and depends on a cis site in the xylA reading frame

Authors

  • Sabine Jacob
    • Lehrstuhl für MikrobiologieInstitut für Mikrobiologie and Biochemie der Friedrich-Alexander Universität Erlangen-Nürnberg
  • Rudolf Allmansberger
    • Lehrstuhl für MikrobiologieInstitut für Mikrobiologie and Biochemie der Friedrich-Alexander Universität Erlangen-Nürnberg
  • Dagmar Gärtner
    • Lehrstuhl für MikrobiologieInstitut für Mikrobiologie and Biochemie der Friedrich-Alexander Universität Erlangen-Nürnberg
  • Wolfgang Hillen
    • Lehrstuhl für MikrobiologieInstitut für Mikrobiologie and Biochemie der Friedrich-Alexander Universität Erlangen-Nürnberg
Article

DOI: 10.1007/BF00272155

Cite this article as:
Jacob, S., Allmansberger, R., Gärtner, D. et al. Molec. Gen. Genet. (1991) 229: 189. doi:10.1007/BF00272155

Summary

The Bacillus subtilis xyl operon encoding enzymes for xylose utilization is repressed in the absence of xylose and in the presence of glucose. Transcriptional fusions of spoVG-lacZ to this operon show regulation of β-galactosidase expression by glucose, indicating that glucose repression operates at the level of transcription. A similar result is obtained when glucose is replaced by glycerol, thus defining a general catabolite repression mechanism. A deletion of xylR, which encodes the xylose-sensitive repressor of the operon, does not affect glucose repression. The cis element mediating glucose repression was identified by Bal31 deletion analysis. It is confined to a 34 by segment located at position + 125 downstream of the xyl promoter in the coding sequence for xylose isomerase. Cloning of this segment in the opposite orientation leads to reduced catabolite repression. The homology of this element to various proposed consensus sequences for catabolite repression in B. subtilis is discussed.

Key words

Bacillus subtilisspoVG-lacZ fusionsRegulation of transcriptionGlucose repressionTranslational coupling

Copyright information

© Springer-Verlag 1991