Glutamyl-tRNA reductase of Chlorobium vibrioforme is a dissociable homodimer that contains one tightly bound heme per subunit.

ABSTRACT: delta-Aminolevulinic acid, the biosynthetic precursor of tetrapyrroles, is synthesized from glutamate via the tRNA-dependent five-carbon pathway in the green sulfur bacterium Chlorobium vibrioforme. The enzyme glutamyl-tRNA reductase (GTR), encoded by the hemA gene, catalyzes the first committed step in this pathway, which is the reduction of tRNA-bound glutamate to produce glutamate 1-semialdehyde. To characterize the GTR protein, the hemA gene from C. vibrioforme was cloned into expression plasmids that added an N-terminal His(6) tag to the expressed protein. The His-tagged GTR protein was purified using Ni affinity column chromatography. GTR was observable as a 49-kDa band on sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) gels. The native molecular mass, as determi

SUBMITTER: Srivastava A 

PROVIDER: S-EPMC1151790 | biostudies-literature | 2005 Jul

REPOSITORIES: biostudies-literature