Disease relevance of nodH

• It has been proposed that the bacterial genes nodABC, common to all Rhizobium, are required for synthesis of an oligosaccharide factor, which is converted to a sulphated form (NodRm-1) by the products of the R. meliloti-specific genes nodH and nodQ1-5; NodRm-1 elicits host-specific plant responses [1].
• Using protein extracts and partially purified recombinant NodH protein obtained from Escherichia coli expressing the R. meliloti nodH gene, we demonstrate here NodH-dependent in vitro sulfotransferase activity [2].
• BACKGROUND: The NodH sulfotransferase from Sinorhizobium meliloti has been used to radiolabel lipochitooligosaccharidic (LCO) Nod factor signals with 35S from inorganic sulfate in a two-step enzymatic procedure [3].

High impact information on nodH

• Upstream of three inducible nod gene clusters, nodABC, nodFE, and nodH, is a highly conserved sequence referred to as a 'nod box.' The upstream sequences have no other obvious similarity [4].
• A conserved nucleotide sequence was found around 200 bp upstream of the translation start of nodF, nodH and nodA [5].
• The DNA sequence analysis, in conjunction with previous genetic data, allowed identification of four nod genes designated as E, F, G and H. nodH is divergently transcribed with respect to nodFE and nodG [5].
• The nodH product contains a rare sequence of four contiguous proline residues [5].
• This sulfate modification requires the action of three gene products: nodH, which catalyzes the sulfonyl transfer, and nodPQ, which produce the activated form of sulfate, 3'-phosphoadenosine-5'-phosphosulfate [6].

Biological context of nodH

• Complementation studies implied, however, that the phenotype on alfalfa correlated with the nodH locus [7].
• In contrast, induction of nodule organogenesis, which can be triggered from a distance, seemed to be controlled by common nodABC genes and not to require specific nod genes nodFE and nodH [8].
• The strain N33 genome contains one copy of nodH and two copies of nodPQ that are homologous to those genes in Rhizobium meliloti [9].
• Transfer of an IncP plasmid carrying the Rhizobium meliloti nodFE, nodG, and nodH genes to Rhizobium trifolii enabled R. trifolii to nodulate alfalfa (Medicago sativa), the normal host of R. meliloti [10].
• NodD1 and NodD3 both interacted with the nodABC, nodFE, and nodH promoters and protected from cleavage an extensive piece of DNA, including the nod box, from approximately -20 to -75 from the transcription start site for each of the three promoters [11].

Associations of nodH with chemical compounds

• RESULTS: The limiting step has been shown to be the sulfation of ATP and its subsequent conversion into PAPS (first step), the sulfate donor for the NodH sulfotransferase activity (second step) [3].

Other interactions of nodH

• Analysis of Rhizobium meliloti nodulation mutant WL131: novel insertion sequence ISRm3 in nodG and altered nodH protein product [7].

Analytical, diagnostic and therapeutic context of nodH

• Common nodABC genes as well as host-specific nodH and nodQ genes were shown recently, using bioassays, to be involved in the production of extracellular Nod signals [12].

References