Functional redundancy of genes for sulphate activation enzymes in Rhizobium sp. BR816.

TitleFunctional redundancy of genes for sulphate activation enzymes in Rhizobium sp. BR816.
Publication TypeJournal Article
Year of Publication1997
AuthorsLaeremans, T., N. Coolsaet, C. Verreth, C. Snoeck, N. Hellings, J. Vanderleyden, and E. Martínez-Romero
JournalMicrobiology
Volume143 ( Pt 12)
Pagination3933-42
Date Published1997 Dec
ISSN1350-0872
KeywordsBacterial Proteins, Base Sequence, Cloning, Molecular, DNA Primers, Drug Resistance, Microbial, Genes, Bacterial, Molecular Sequence Data, Multienzyme Complexes, Mutagenesis, Insertional, Nitrogen Fixation, Open Reading Frames, Plasmids, Polymerase Chain Reaction, Restriction Mapping, Rhizobium, Sequence Homology, Nucleic Acid, Sinorhizobium meliloti, Sulfate Adenylyltransferase, Sulfates, Symbiosis
Abstract

The broad-host-range, heat-tolerant Rhizobium strain BR816 produces sulphated Nod metabolites. Two ORFs highly homologous to the Sinorhizobium meliloti nodPQ genes were isolated and sequenced. It was found that Rhizobium sp. BR816 contained two copies of these genes; one copy was localized on the symbiotic plasmid, the other on the megaplasmid. Both nodP genes were interrupted by insertion of antibiotic resistance cassettes, thus constructing a double nodP1P2 mutant strain. However, no detectable differences in Nod factor TLC profile from this mutant were observed as compared to the wild-type strain. Additionally, plant inoculation experiments did not reveal differences between the mutant strain and the wild-type. It is proposed that a third, functionally homologous locus complements mutations in the Nod factor sulphation genes. Southern blot analysis suggested that this locus contains genes necessary for the sulphation of amino acids.

Alternate JournalMicrobiology (Reading, Engl.)
PubMed ID9421916