Open AccessThe algT (algU) gene of Pseudomonas aeruginosa, a key regulator involved in alginate biosynthesis, encodes an alternative sigma factor (sigma E).
Author(s) -
C. Douglas Hershberger,
Rui-Ling Ye,
Matthew R. Parsek,
Zhidong Xie,
Ananda M. Chakrabarty
Publication year - 1995
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.011
H-Index - 771
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.92.17.7941
Subject(s) - sigma factor , biology , rna polymerase , pseudomonas aeruginosa , gene , escherichia coli , promoter , transcription (linguistics) , nucleic acid sequence , microbiology and biotechnology , genetics , bacteria , gene expression , linguistics , philosophy
Chronic infection by alginate-producing (mucoid) Pseudomonas aeruginosa is the leading cause of mortality among cystic fibrosis (CF) patients. During the course of sustained infection, the production of an alginate capsule protects the bacteria and allows them to persist in the CF lung. One of the key regulators of alginate synthesis is the algT (algU) gene encoding a putative alternative sigma factor (sigma E). AlgT was hyperproduced and purified from Escherichia coli. The N-terminal sequence of the purified protein matched perfectly with that predicted from the DNA sequence. The purified protein, in the presence of E. coli RNA polymerase core enzyme, was able to initiate transcription of an algT promoter. Deletion of the -35 region of this promoter abolished this activity in vitro as well as in vivo. These data indicate that the algT gene encodes a sigma factor that is autoregulatory.