1BW9

PHENYLALANINE DEHYDROGENASE STRUCTURE IN TERNARY COMPLEX WITH NAD+ AND PHENYLPYRUVATE

Summary for 1BW9

• Entry DOI: 10.2210/pdb1bw9/pdb
• Descriptor: PHENYLALANINE DEHYDROGENASE, NICOTINAMIDE-ADENINE-DINUCLEOTIDE, 3-PHENYLPYRUVIC ACID, ... (10 entities in total)
• Functional Keywords: amino acid dehydrogenase, oxidative deamination mechanism
• Biological source: Rhodococcus sp.; More
• Total number of polymer chains: 2
• Total formula weight: 75476.67

Authors

Vanhooke, J.L.,Thoden, J.B.,Brunhuber, N.M.W.,Blanchard, J.L.,Holden, H.M. (deposition date: 1998-10-01, release date: 1999-05-18, Last modification date: 2024-02-07)

Primary citation

Vanhooke, J.L.,Thoden, J.B.,Brunhuber, N.M.,Blanchard, J.S.,Holden, H.M.
Phenylalanine dehydrogenase from Rhodococcus sp. M4: high-resolution X-ray analyses of inhibitory ternary complexes reveal key features in the oxidative deamination mechanism.
Biochemistry, 38:2326-2339, 1999

PubMed Abstract: The molecular structures of recombinant L-phenylalanine dehydrogenase from Rhodococcus sp. M4 in two different inhibitory ternary complexes have been determined by X-ray crystallographic analyses to high resolution. Both structures show that L-phenylalanine dehydrogenase is a homodimeric enzyme with each monomer composed of distinct globular N- and C-terminal domains separated by a deep cleft containing the active site. The N-terminal domain binds the amino acid substrate and contributes to the interactions at the subunit:subunit interface. The C-terminal domain contains a typical Rossmann fold and orients the dinucleotide. The dimer has overall dimensions of approximately 82 A x 75 A x 75 A, with roughly 50 A separating the two active sites. The structures described here, namely the enzyme.NAD+.phenylpyruvate, and enzyme. NAD+.beta-phenylpropionate species, represent the first models for any amino acid dehydrogenase in a ternary complex. By analysis of the active-site interactions in these models, along with the currently available kinetic data, a detailed chemical mechanism has been proposed. This mechanism differs from those proposed to date in that it accounts for the inability of the amino acid dehydrogenases, in general, to function as hydroxy acid dehydrogenases.

PubMed: 10029526
DOI: 10.1021/bi982244q

Experimental method

X-RAY DIFFRACTION (1.5 Å)