Structural basis for regulation of rhizobial nodulation and symbiosis gene expression by the regulatory protein NolR.

ABSTRACT: The symbiosis between rhizobial microbes and host plants involves the coordinated expression of multiple genes, which leads to nodule formation and nitrogen fixation. As part of the transcriptional machinery for nodulation and symbiosis across a range of Rhizobium, NolR serves as a global regulatory protein. Here, we present the X-ray crystal structures of NolR in the unliganded form and complexed with two different 22-base pair (bp) double-stranded operator sequences (oligos AT and AA). Structural and biochemical analysis of NolR reveals protein-DNA interactions with an asymmetric operator site and defines a mechanism for conformational switching of a key residue (Gln56) to accommodate variation in target DNA sequences from diverse rhizobial genes for nodulation and symbiosis. This confor

SUBMITTER: Lee SG 

PROVIDER: S-EPMC4035926 | biostudies-literature | 2014 Apr

REPOSITORIES: biostudies-literature