2YKY

Structural Determinants of the Beta-Selectivity of a Bacterial Aminotransferase

Summary for 2YKY

• Entry DOI: 10.2210/pdb2yky/pdb
• Related: 2YKU 2YKV 2YKX 4AO4
• Descriptor: BETA-TRANSAMINASE, 1,2-ETHANEDIOL, PYRIDOXAL-5'-PHOSPHATE, ... (7 entities in total)
• Functional Keywords: transferase
• Biological source: MESORHIZOBIUM SP. LUK
• Total number of polymer chains: 3
• Total formula weight: 151451.99

Authors

Wybenga, G.G.,Crismaru, C.G.,Janssen, D.B.,Dijkstra, B.W. (deposition date: 2011-05-30, release date: 2012-05-30, Last modification date: 2024-05-01)

Primary citation

Wybenga, G.G.,Crismaru, C.G.,Janssen, D.B.,Dijkstra, B.W.
Structural Determinants of the Beta-Selectivity of a Bacterial Aminotransferase.
J.Biol.Chem., 287:28495-, 2012

PubMed Abstract: Chiral β-amino acids occur as constituents of various natural and synthetic compounds with potentially useful bioactivities. The pyridoxal 5'-phosphate (PLP)-dependent S-selective transaminase from Mesorhizobium sp. strain LUK (MesAT) is a fold type I aminotransferase that can be used for the preparation of enantiopure β-Phe and derivatives thereof. Using x-ray crystallography, we solved structures of MesAT in complex with (S)-β-Phe, (R)-3-amino-5-methylhexanoic acid, 2-oxoglutarate, and the inhibitor 2-aminooxyacetic acid, which allowed us to unveil the molecular basis of the amino acid specificity and enantioselectivity of this enzyme. The binding pocket of the side chain of a β-amino acid is located on the 3'-oxygen side of the PLP cofactor. The same binding pocket is utilized by MesAT to bind the α-carboxylate group of an α-amino acid. A β-amino acid thus binds in a reverse orientation in the active site of MesAT compared with an α-amino acid. Such a binding mode has not been reported before for any PLP-dependent aminotransferase and shows that the active site of MesAT has specifically evolved to accommodate both β- and α-amino acids.

PubMed: 22745123
DOI: 10.1074/JBC.M112.375238

Experimental method

X-RAY DIFFRACTION (1.69 Å)