Skip to main content
padlock icon - secure page this page is secure

Free Content Role of PdxR in the activation of vitamin B6 biosynthesis in Listeria monocytogenes

Download Article:
 Download
(PDF)
 
L isteria monocytogenes PdxR is a member of the poorly characterized but widespread group of MocR/GabR‐type chimeric bacterial proteins that have DNA‐binding and aminotransferase‐like domains. Using mutational analysis, real‐time RT‐PCR, transcriptional fusions, gel‐shift assays, DNase I footprinting, and in vitro transcription, it was shown that PdxR is a direct activator of the pdxST operon, transcribed divergently from pdxR and responsible for the de novo synthesis of pyridoxal 5′‐phosphate (PLP), the major active form of vitamin B6. PLP acts as an anti‐activator of PdxR and is the only effector required to reduce the activity of PdxR. PdxR is also a negative autoregulator, and its ability to repress is increased by PLP. A dyad‐symmetry sequence, which overlaps the −35 region of the pdxS promoter and lies downstream of the pdxR transcription start point, serves as an important element of the PdxR binding site. Unexpectedly, some mutations in this activator binding site, disrupting the dyad‐symmetry element, caused constitutive, B6‐independent expression from the pdxS promoter. The data suggest that PdxR‐like proteins, for which PLP plays just a signalling role, form a separate functional group among the MocR/GabR‐type proteins.
No References
No Citations
No Supplementary Data
No Article Media
No Metrics

Document Type: Research Article

Publication date: June 1, 2014

  • Access Key
  • Free content
  • Partial Free content
  • New content
  • Open access content
  • Partial Open access content
  • Subscribed content
  • Partial Subscribed content
  • Free trial content
Cookie Policy
X
Cookie Policy
Ingenta Connect website makes use of cookies so as to keep track of data that you have filled in. I am Happy with this Find out more