2isl
From Proteopedia
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| , resolution 2.9Å | |||||||
|---|---|---|---|---|---|---|---|
| Ligands: | and | ||||||
| Gene: | bluB (Sinorhizobium meliloti) | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
BluB bound to reduced flavin (FMNH2) and molecular oxygen. (clear crystal form)
Overview
An insight into a previously unknown step in B(12) biosynthesis was unexpectedly obtained through our analysis of a mutant of the symbiotic nitrogen fixing bacterium Sinorhizobium meliloti. This mutant was identified based on its unusually bright fluorescence on plates containing the succinoglycan binding dye calcofluor. The mutant contains a Tn5 insertion in a gene that has not been characterized previously in S. meliloti. The closest known homolog is the bluB gene of Rhodobacter capsulatus, which is implicated in the biosynthesis of B(12) (cobalamin). The S. meliloti bluB mutant is unable to grow in minimal media and fails to establish a symbiosis with alfalfa, and these defects can be rescued by the addition of vitamin B(12) (cyanocobalamin) or the lower ligand of cobalamin, 5,6-dimethylbenzimidazole (DMB). Biochemical analysis demonstrated that the bluB mutant does not produce cobalamin unless DMB is supplied. Sequence comparison suggests that BluB is a member of the NADH/flavin mononucleotide (FMN)-dependent nitroreductase family, and we propose that it is involved in the conversion of FMN to DMB.
About this Structure
2ISL is a Single protein structure of sequence from Sinorhizobium meliloti. Full crystallographic information is available from OCA.
Reference
Sinorhizobium meliloti bluB is necessary for production of 5,6-dimethylbenzimidazole, the lower ligand of B12., Campbell GR, Taga ME, Mistry K, Lloret J, Anderson PJ, Roth JR, Walker GC, Proc Natl Acad Sci U S A. 2006 Mar 21;103(12):4634-9. Epub 2006 Mar 1. PMID:16537439
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