Regulatory system of the protocatechuate 4,5-cleavage pathway genes essential for lignin downstream catabolism.

ABSTRACT: Sphingobium sp. strain SYK-6 converts various lignin-derived biaryls with guaiacyl (4-hydroxy-3-methoxyphenyl) and syringyl (4-hydroxy-3,5-dimethoxyphenyl) moieties to vanillate and syringate. These compounds are further catabolized through the protocatechuate (PCA) 4,5-cleavage (PCA45) pathway. In this article, the regulatory system of the PCA45 pathway is described. A LysR-type transcriptional regulator (LTTR), LigR, activated the transcription of the ligK-orf1-ligI-lsdA and ligJABC operons in the presence of PCA or gallate (GA), which is an intermediate metabolite of vanillate or syringate, respectively, and repressed transcription of its own gene. LigR bound to the positions -77 to -51 and -80 to -48 of the ligK and ligJ promoters, respectively, and induced DNA bending. In the presence

SUBMITTER: Kamimura N 

PROVIDER: S-EPMC2897667 | biostudies-literature | 2010 Jul

REPOSITORIES: biostudies-literature