Molecular cloning of a gene region from Bradyrhizobium japonicum essential for lipopolysaccharide synthesis.
The gene region cloned from a lipopolysaccharide (LPS) mutant carrying the Tn5 and flanking DNA sequences was used as a probe to screen a gene bank prepared from wild-type Bradyrhizobium japonicum strain 61A101C and to isolate the corresponding wild-type LPS-gene region. By cross-hybridization experiments the LPS-gene region did not appear to be closely linked to previously cloned nodulation genes. A detailed restriction map of the LPS-gene region (5.5-kb EcoRI genomic fragment) was established and the mutation site was localized to be in a 300-bp PvuI/PstI restriction fragment. In genomic Southern-blot analysis of various rhizobia, the LPS-gene region was found to be conserved among all the slow-growing bradyrhizobia, but not the fast-growing rhizobia. The different groups of slow-growing bradyrhizobia are polymorphic for restriction-fragment length at the LPS-gene region.
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J S
JS
Department of Microbiology, University of British Columbia, Vancouver, Canada.
D015139:Blotting, Southern; D003001:Cloning, Molecular; D005798:Genes, Bacterial; D015698:Genomic Library; D008070:Lipopolysaccharides / Q000235:genetics*; D015183:Restriction Mapping; D012230:Rhizobiaceae / Q000235:genetics*
D008070:Lipopolysaccharides