REVIEW | doi:10.20944/preprints201611.0087.v1
Online: 17 November 2016 (10:40:58 CET)
Oxidative stress occurs when cells are exposed to elevated levels of reactive oxygen species that could damage biological molecules. One bacterial response to oxidative stress involves disulfide bond formation either between protein thiols or between protein thiols and low-molecular-weight thiols. Bacillithiol was recently identified as a major low-molecular-weight thiol in Bacillus subtilis and related Firmicutes. Four genes (bshA, bshB1, bshB2 and bshC) are involved in bacillithiol biosynthesis. The bshA and bshB1 genes are part of a seven-gene operon (ypjD), which includes the essential gene cca, encoding CCA-tRNA nucleotidyltransferase. The inclusion of cca in the operon containing bacillithiol biosynthetic genes suggests that the integrity of the 3’ terminus of tRNAs may also be important in oxidative stress. Addition of the 3´ terminal CCA sequence by CCA-tRNA nucleotidyltransferase to give a mature tRNA and functional molecules ready for aminoacylation plays an essential role during translation and expression of the genetic code. Any defects in these processes, for example, the accumulation of shorter and defective tRNAs under oxidative stress, could exert a deleterious effect on cells. This review summarizes the physiological link between tRNACys regulation and oxidative stress in Bacillus.