2isj: Difference between revisions

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==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.

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==

Line 13:

[[Category: Single protein]]

[[Category: Sinorhizobium meliloti]]

[[Category: Howard-Jones, A.R.]]

[[Category: Howard-Jones, A R.]]

[[Category: Larsen, N.A.]]

[[Category: Larsen, N A.]]

[[Category: Taga, M.E.]]

[[Category: Taga, M E.]]

[[Category: Walker, G.C.]]

[[Category: Walker, G C.]]

[[Category: Walsh, C.T.]]

[[Category: Walsh, C T.]]

[[Category: FMN]]

[[Category: flavin]]

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[[Category: vitamin b12]]

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@@ Line 4: / Line 4: @@
 ==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.
+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==
@@ Line 13: / Line 13: @@
 [[Category: Single protein]]
 [[Category: Sinorhizobium meliloti]]
-[[Category: Howard-Jones, A.R.]]
+[[Category: Howard-Jones, A R.]]
-[[Category: Larsen, N.A.]]
+[[Category: Larsen, N A.]]
-[[Category: Taga, M.E.]]
+[[Category: Taga, M E.]]
-[[Category: Walker, G.C.]]
+[[Category: Walker, G C.]]
-[[Category: Walsh, C.T.]]
+[[Category: Walsh, C T.]]
 [[Category: FMN]]
 [[Category: flavin]]
@@ Line 25: / Line 25: @@
 [[Category: vitamin b12]]
-''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Tue Jan 29 20:45:55 2008''
+''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 17:55:30 2008''