当前位置： SCI文献检索 > PLoS Genetics期刊下所有文献 > Transcription and translation of the sigG gene is tuned for proper execution of the switch from early to late gene expression in the developing Bacillus subtilis spore.

Transcription and translation of the sigG gene is tuned for proper execution of the switch from early to late gene expression in the developing Bacillus subtilis spore.

Abstract：

:A cascade of alternative sigma factors directs developmental gene expression during spore formation by the bacterium Bacillus subtilis. As the spore develops, a tightly regulated switch occurs in which the early-acting sigma factor σF is replaced by the late-acting sigma factor σG. The gene encoding σG (sigG) is transcribed by σF and by σG itself in an autoregulatory loop; yet σG activity is not detected until σF-dependent gene expression is complete. This separation in σF and σG activities has been suggested to be due at least in part to a poorly understood intercellular checkpoint pathway that delays sigG expression by σF. Here we report the results of a careful examination of sigG expression during sporulation. Unexpectedly, our findings argue against the existence of a regulatory mechanism to delay sigG transcription by σF and instead support a model in which sigG is transcribed by σF with normal timing, but at levels that are very low. This low-level expression of sigG is the consequence of several intrinsic features of the sigG regulatory and coding sequence-promoter spacing, secondary structure potential of the mRNA, and start codon identity-that dampen its transcription and translation. Especially notable is the presence of a conserved hairpin in the 5' leader sequence of the sigG mRNA that occludes the ribosome-binding site, reducing translation by up to 4-fold. Finally, we demonstrate that misexpression of sigG from regulatory and coding sequences lacking these features triggers premature σG activity in the forespore during sporulation, as well as inappropriate σG activity during vegetative growth. Altogether, these data indicate that transcription and translation of the sigG gene is tuned to prevent vegetative expression of σG and to ensure the precise timing of the switch from σF to σG in the developing spore.

journal_name

PLoS Genet

journal_title

PLoS genetics

authors

Mearls EB,Jackter J,Colquhoun JM,Farmer V,Matthews AJ,Murphy LS,Fenton C,Camp AH

doi

10.1371/journal.pgen.1007350

subject

Has Abstract

pub_date

2018-04-27 00:00:00

pages

e1007350

issue

eissn

1553-7390

issn

1553-7404

pii

PGENETICS-D-18-00261

journal_volume

pub_type

杂志文章

在线工具

Transcription and translation of the sigG gene is tuned for proper execution of the switch from early to late gene expression in the developing Bacillus subtilis spore.