Advertisement

Molecular and General Genetics MGG

, Volume 256, Issue 1, pp 63–71 | Cite as

Characterization of an lrp-like (IrpC ) gene from Bacillus subtilis

  • C. Beloin
  • S. Ayora
  • R. Exley
  • L. Hirschbein
  • N. Ogasawara
  • Y. Kasahara
  • J. C. Alonso
  • F. Le Hégarat
ORIGINAL PAPER

Abstract

In the course of the Bacillus subtilis genome sequencing project, we identified an open reading frame encoding a putative 16.4 kDa protein. This protein shows, respectively, 34% and 25% identity with the Escherichia coli regulatory proteins Lrp and AsnC. Phylogenetic analysis suggests that it represents a new group in the AsnC-Lrp family. Sequence comparisons, as well as immunodetection experiments, lead to the conclusion that the product of this B. subtilislrp-likegene is a bona fide Lrp protein – the first one to be detected in gram-positive bacteria. When expressed in E.␣coli, the B. subtilis Lrp-like protein is able to repress, by about two-fold, the expression of the ilvIH operon which is normally regulated by E. coli Lrp, indicating functional similarity in their regulatory targets. Vegetative growth of a B. subtilis lrp-like mutant is not affected in rich medium. However, the lrp-like mutation causes a transitory inhibition of growth in minimal medium in the presence of valine and isoleucine, which is relieved by leucine. This points to a possible role in regulation of amino acid metabolism. In addition, sporogenesis occurs earlier in the lrp-like mutant than in the reference strain, implying that the B. subtilis Lrp-like protein plays a role in the growth phase transition.

Key words asnC Regulation of transcription Amino acid metabolism Growth phase transition Sporulation 

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

Copyright information

© Springer-Verlag Berlin Heidelberg 1997

Authors and Affiliations

  • C. Beloin
    • 1
  • S. Ayora
    • 2
  • R. Exley
    • 1
  • L. Hirschbein
    • 1
  • N. Ogasawara
    • 3
  • Y. Kasahara
    • 3
  • J. C. Alonso
    • 2
  • F. Le Hégarat
    • 1
  1. 1.Institut de Génétique et Microbiologie, Université Paris XI, Bât. 409, 91405 Orsay Cedex, France Fax: +33-1-6915-78 08; e-mail: lehegarat@igmors.u-psud.frFR
  2. 2.Centro Nacional de Biotecnologìa, CSIC, Campus Universidad Autónoma de Madrid, Cantoblanco, 28049 Madrid, SpainES
  3. 3.Department of Molecular Biology, Graduate School of Biological Sciences, Nara Institute of Science and Technology 8916-5, Takayamacho, Ikoma 630-01, JapanJP

Personalised recommendations