Interaction of NahR, a LysR-type transcriptional regulator, with the alpha subunit of RNA polymerase in the naphthalene degrading bacterium, Pseudomonas putida NCIB 9816-4

Abstract

NahR, a LysR-type transcriptional regulator, is required for expression of naphthalene catabolic operons. However, detailed mechanisms of transcriptional activation by NahR. are poorly understood. Many transcriptional activators make direct contact with RNA polymerase (RNAP) to initiate transcription. We investigated the hypothesis that direct contact between NahR and the a subunit of RNAP (alphaRNAP) may be involved in expression of the naphthalene catabolic operons in Pseudomonas putida NCIB 9816-4. Interactions between the NahR and alphaRNAP in P. putida NCIB 9816-4 were analyzed using the yeast two-hybrid system. The results obtained indicate that protein-protein interactions occur between alphaRNAP and the NahR. Gene activation by NahR is consistent with the general transcriptional mechanism of class I transcription factors, which function by contacting alphaRNAP. (C) 2002 Federation of European Microbiological Societies. Published by Elsevier Science B.V. All rights reserved.