This Article Full Text 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 Cervantes, M. Articles by Murillo, F. J. Search for Related Content PubMed PubMed Citation Articles by Cervantes, M. Articles by Murillo, F. J.

 Previous Article  |  Next Article 

Journal of Bacteriology, April 2002, p. 2215-2224, Vol. 184, No. 8
0021-9193/02/$04.00+0     DOI: 10.1128/JB.184.8.2215-2224.2002
Copyright © 2002, American Society for Microbiology. All Rights Reserved.

Role for Vitamin B₁₂ in Light Induction of Gene Expression in the Bacterium Myxococcus xanthus

Departamento de Genética y Microbiología, Facultad de Biología, Universidad de Murcia, 30100 Murcia, Spain

Received 17 July 2001/ Accepted 21 January 2002

A light-inducible promoter (P_B) drives the carB operon (carotenoid genes) of the bacterium Myxococcus xanthus. A gene encoding a regulator of carotenoid biosynthesis was identified by studying mutant strains carrying a transcriptional fusion to P_B and deletions in three candidate genes. Our results prove that the identified gene, named carA, codes for a repressor of the P_B promoter in the dark. They also show that the carA gene product does not participate in the light activation of two other promoters connected with carotenoid synthesis or its regulation in M. xanthus. CarA is a novel protein consisting of a DNA-binding domain of the family of MerR helix-turn-helix transcriptional regulators, directly joined to a cobalamin-binding domain. In support of this, we report here that the presence of vitamin B₁₂ or some other cobalamin derivatives is absolutely required for activation of the P_B promoter by light.

This article has been cited by other articles:

• Galbis-Martinez, L., Galbis-Martinez, M., Murillo, F. J., Fontes, M. (2008). An anti-antisigma factor in the response of the bacterium Myxococcus xanthus to blue light. Microbiology 154: 895-904 [Abstract] [Full Text]  
• Oltean, S., Banerjee, R. (2005). A B12-responsive Internal Ribosome Entry Site (IRES) Element in Human Methionine Synthase. J. Biol. Chem. 280: 32662-32668 [Abstract] [Full Text]  
• Perez-Marin, M. C., Lopez-Rubio, J. J., Murillo, F. J., Elias-Arnanz, M., Padmanabhan, S. (2004). The N Terminus of Myxococcus xanthus CarA Repressor Is an Autonomously Folding Domain That Mediates Physical and Functional Interactions with Both Operator DNA and Antirepressor Protein. J. Biol. Chem. 279: 33093-33103 [Abstract] [Full Text]  
• Gomelsky, L., Sram, J., Moskvin, O. V., Horne, I. M., Dodd, H. N., Pemberton, J. M., McEwan, A. G., Kaplan, S., Gomelsky, M. (2003). Identification and in vivo characterization of PpaA, a regulator of photosystem formation in Rhodobacter sphaeroides. Microbiology 149: 377-388 [Abstract] [Full Text]