SOS induction in mycobacteria: analysis of the DNA-binding activity of a LexA-like repressor and its role in DNA damage induction of the recA gene from Mycobacterium smegmatis

Molecular Microbiology
S I DurbachValerie Mizrahi

Abstract

The protein encoded by the lexA gene from Mycobacterium leprae was overproduced in Escherichia coli. The recombinant protein bound to the promoter regions of the M. leprae lexA, M. leprae recA and M. smegmatis recA genes at sites with the sequences 5'-GAACACATGTTT and 5'-GAACAGGTGTTC, which belong to the 'Cheo box' family of binding sites recognized by the SOS repressor from Bacillus subtilis. Gel mobility shift assays were used to confirm that proteins with the same site specificity of DNA binding are also present in Mycobacterium tuberculosis and M. smegmatis. Complex formation was impaired by mutagenic disruption of the dyad symmetry of the M. smegmatis recA Cheo box. LexA binding was also inhibited by preincubation of the M. smegmatis and M. tuberculosis extracts with anti-M. leprae LexA antibodies, suggesting that the mycobacterial LexA proteins are functionally conserved at the level of DNA binding. Finally, exposure of M. smegmatis to DNA-damaging agents resulted in induction of the M. smegmatis recA promoter with concomitant loss of DNA binding of LexA to its Cheo box, confirming that this organism possesses the key regulatory elements of a functional SOS induction system.

Citations

Jul 15, 1998·Molecular Microbiology·A R Fernández de HenestrosaJ Barbé
Aug 4, 2006·Journal of Bacteriology·Patricia C BrooksElaine O Davis
Dec 21, 2010·Journal of Bacteriology·Katherine L SmollettElaine O Davis
Jul 19, 2016·Microbiology and Immunology·María M BigiFabiana Bigi
Oct 27, 2017·Scientific Reports·Begonia Fudrini OlivenciaFrank Imkamp
Oct 22, 1998·Molecular Microbiology·V Mizrahi, S J Andersen
Dec 12, 2001·Microbiology·K G PapavinasasundaramE O Davis
Apr 29, 1998·Journal of Bacteriology·K W WinterlingR Woodgate
Apr 1, 2017·Microbiology Spectrum·Zanele DitseDigby F Warner
Jan 1, 1997·Tubercle and Lung Disease : the Official Journal of the International Union Against Tuberculosis and Lung Disease·M A MulderL M Steyn

❮ Previous
Next ❯

Related Concepts

Related Feeds

Bacterial Respiration

This feed focuses on cellular respiration in bacteria, known as bacterial respiration. Discover the latest research here.