Role of the Single Regulator MrsR1 and the Two-Component System MrsR2/K2 in the Regulation of Mersacidin Production and Immunity
AUTOR(ES)
Guder, André
FONTE
American Society for Microbiology
RESUMO
The lantibiotic mersacidin is an antimicrobial peptide of 20 amino acids which inhibits bacterial cell wall biosynthesis by binding to the precursor molecule lipid II and which is produced by Bacillus sp. strain HIL Y-85,54728. The structural gene of mersacidin as well as accessory genes is organized in a biosynthetic gene cluster which is located on the chromosome and contains three open reading frames with similarities to regulatory proteins: mrsR2 and mrsK2 encode two proteins with homology to bacterial two-component systems, and mrsR1 shows similarity to a response regulator. Both mrsR2/K2 and mrsR1 were inactivated by insertion of an antibiotic resistance marker. Disruption of mrsR1 resulted in loss of mersacidin production; however, producer self-protection was not impaired. In contrast, inactivation of mrsR2/K2 led to an increased susceptibility to mersacidin whereas biosynthesis of the lantibiotic remained unaffected. Binding of mersacidin to intact cells was significantly enhanced in the mrsR2/K2 knockout mutant. Reverse transcription-PCR analysis from total RNA preparations showed that in contrast to the wild-type strain, the structural genes of the ABC transporter MrsFGE were not transcribed in the knockout mutant. It was therefore concluded that producer self-protection against mersacidin is conferred by the ABC transporter MrsFGE and that the transcription of mrsFGE is regulated by MrsR2/K2, whereas production of the antibacterial peptide is solely activated by MrsR1.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=126572Documentos Relacionados
- A small protein that mediates the activation of a two-component system by another two-component system
- Regulation of Virulence by a Two-Component System in Group B Streptococcus†
- OmpR Regulates the Two-Component System SsrA-SsrB in Salmonella Pathogenicity Island 2
- Is cross regulation by phosphorylation of two-component response regulator proteins important in bacteria?
- Role of the Two-Component Regulator CpxAR in the Virulence of Salmonella enterica Serotype Typhimurium