A conditional expression system has been developed using the isopropyl-beta-d-thiogalactopyranoside (IPTG)-inducible Pspac promoter to validate essential genes of Staphylococcus aureus in vivo. The system has been applied to prove the essentiality of ligA and to evaluate the function of tarI, which was found to be essential in vitro but not in vivo.

Construction of YkoU and YkoV mutant B. subtilis strains. Strains BFS1845 and BFS1846 were constructed using the plasmid pMUTIN4 (S1). PCR-amplified fragments of an internal region of YkoU or YkoV were cloned into the Eco RI–Bam HI sites of pMUTIN4. A 32–base pair (bp) PCR fragment of the YkoU gene, synthesized using the primers SM44 (5 &&**$$77&&$$$7**$&7**$&& DQG 60 CGCGGATCCGACATATCCTCACAGAC...

Bacterial genome sequencing has revealed a novel family of P-loop GTPases that are often essential for growth. Accumulating evidence suggests that these proteins are involved in biogenesis of the 30S or 50S ribosomal subunits. YqeH is a member of this Obg/Era GTPase family, with its function remains to be uncovered. Here, we present results showing that YqeH is involved in the 30S subunit bioge...

Bacteria are known to cope with environmental changes by using alternative sigma factors binding to RNA polymerase core enzyme. Sigma factor is one of the targets to modify transcription regulation in bacteria and to influence production capacities. In this study, the effect of overexpressing each annotated sigma factor gene in Corynebacterium glutamicum WT was assayed using an IPTG inducible p...