Journal article

Publication year: 2014

Pages: 635-640

Journal: Molecular Microbiology

Volume number: 91

Issue number: 4

ISSN: 0950-382X

Open access status: Bronze

DOI Link: https://doi.org/10.1111/mmi.12490

Publisher: Wiley

Abstract: 
Vitamin B-12 is well known as an enzyme cofactor in the catalysis of many important biological reactions, and the role of B-12 in regulation of bacterial gene expression as a ligand of riboswitches is well established. Only recently evidence has emerged that B-12 can also affect bacterial gene expression by acting as a cofactor of regulatory proteins. In 2011 a role of B-12 as a cofactor of the transcriptional repressor of carotenogenesis, CarH, in Myxococcus xanthus was reported. B-12 is required for light-dependent DNA binding by CarH, which can therefore be considered to be a new type of photoreceptor. Cheng etal. (2014) report the identification of B-12 as a cofactor of the AerR protein in Rhodobacter capsulatus. AerR acts as an antirepressor of the CrtJ protein, which represses photosynthesis genes when binding to its target promoters. As in MyxococcusB(12) may have the role of a chromophore in photoreception, but it is suggested that a main function of AerR is the sensing of B-12. The co-regulation of the pathways is beneficial because the syntheses of B-12, haem and bacteriochlorophylls share common precursors and the accumulation of the free molecules is toxic.

Harvard Citation style: Klug, G. (2014) Beyond catalysis: vitamin B-12 as a cofactor in gene regulation, Molecular Microbiology, 91(4), pp. 635-640. https://doi.org/10.1111/mmi.12490

APA Citation style: Klug, G. (2014). Beyond catalysis: vitamin B-12 as a cofactor in gene regulation. Molecular Microbiology. 91(4), 635-640. https://doi.org/10.1111/mmi.12490