1gpj
Glutamyl-tRNA Reductase from Methanopyrus kandleriGlutamyl-tRNA Reductase from Methanopyrus kandleri
Structural highlights
FunctionHEM1_METKA Catalyzes the NADPH-dependent reduction of glutamyl-tRNA(Glu) to glutamate 1-semialdehyde (GSA). In the absence of NADPH, exhibits substrate esterase activity, leading to the release of glutamate from tRNA.[1] Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedProcesses vital to life such as respiration and photosynthesis critically depend on the availability of tetrapyrroles including hemes and chlorophylls. tRNA-dependent catalysis generally is associated with protein biosynthesis. An exception is the reduction of glutamyl-tRNA to glutamate-1-semialdehyde by the enzyme glutamyl-tRNA reductase. This reaction is the indispensable initiating step of tetrapyrrole biosynthesis in plants and most prokaryotes. The crystal structure of glutamyl-tRNA reductase from the archaeon Methanopyrus kandleri in complex with the substrate-like inhibitor glutamycin at 1.9 A resolution reveals an extended yet planar V-shaped dimer. The well defined interactions of the inhibitor with the active site support a thioester-mediated reduction process. Modeling the glutamyl-tRNA onto each monomer reveals an extensive protein-tRNA interface. We furthermore propose a model whereby the large void of glutamyl-tRNA reductase is occupied by glutamate-1-semialdehyde-1,2-mutase, the subsequent enzyme of this pathway, allowing for the efficient synthesis of 5-aminolevulinic acid, the common precursor of all tetrapyrroles. V-shaped structure of glutamyl-tRNA reductase, the first enzyme of tRNA-dependent tetrapyrrole biosynthesis.,Moser J, Schubert WD, Beier V, Bringemeier I, Jahn D, Heinz DW EMBO J. 2001 Dec 3;20(23):6583-90. PMID:11726494[2] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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