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Structure of a Chimeric Glutamate Dehydrogenase
Structural highlights
FunctionDHE4_ECOLI Catalyzes the reversible oxidative deamination of glutamate to alpha-ketoglutarate and ammonia.[1] [2] E7GGS1_CLOSY Publication Abstract from PubMedGlutamate dehydrogenases (EC 1.4.1.2-4) catalyse the oxidative deamination of L-glutamate to alpha-ketoglutarate using NAD(P)(+) as a cofactor. The bacterial enzymes are hexameric, arranged with 32 symmetry, and each polypeptide consists of an N-terminal substrate-binding segment (domain I) followed by a C-terminal cofactor-binding segment (domain II). The catalytic reaction takes place in the cleft formed at the junction of the two domains. Distinct signature sequences in the nucleotide-binding domain have been linked to the binding of NAD(+) versus NADP(+), but they are not unambiguous predictors of cofactor preference. In the absence of substrate, the two domains move apart as rigid bodies, as shown by the apo structure of glutamate dehydrogenase from Clostridium symbiosum. Here, the crystal structure of a chimaeric clostridial/Escherichia coli enzyme has been determined in the apo state. The enzyme is fully functional and reveals possible determinants of interdomain flexibility at a hinge region following the pivot helix. The enzyme retains the preference for NADP(+) cofactor from the parent E. coli domain II, although there are subtle differences in catalytic activity. Crystal structure of a chimaeric bacterial glutamate dehydrogenase.,Oliveira T, Sharkey MA, Engel PC, Khan AR Acta Crystallogr F Struct Biol Commun. 2016 Jun 1;72(Pt 6):462-6. doi:, 10.1107/S2053230X16007305. Epub 2016 May 23. PMID:27303899[3] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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