2dtj
Crystal structure of regulatory subunit of aspartate kinase from Corynebacterium glutamicum
Structural highlights
FunctionAK_CORGL Catalyzes the phosphorylation of the beta-carboxyl group of aspartic acid with ATP to yield 4-phospho-L-aspartate, which is involved in the branched biosynthetic pathway leading to the biosynthesis of amino acids lysine, threonine, isoleucine and methionine.[1] [2] 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 PubMedAspartate kinase (AK) catalyzes the first step of the biosynthesis of the aspartic acid family amino acids, and is regulated via feedback inhibition by end-products including Thr and Lys. To elucidate the mechanism of this inhibition, we determined the crystal structure of the regulatory subunit of AK from Corynebacterium glutamicum at 1.58 A resolution in the Thr-binding form, the first crystal structure of the regulatory subunit of alpha(2)beta(2)-type AK. The regulatory subunit contains two ACT domain motifs per monomer and is arranged as a dimer. Two non-equivalent ACT domains from different chains form an effector-binding unit that binds a single Thr molecule, and the resulting two effector-binding units of the dimer associate perpendicularly in a face-to-face manner. The regulatory subunit is a monomer in the absence of Thr but becomes a dimer by adding Thr. The dimerization is eliminated in mutant AKs with changes in the Thr-binding region, suggesting that the dimerization induced by Thr binding is a key step in the inhibitory mechanism of AK from C. glutamicum. A putative Lys-binding site and the inhibitory mechanism of CgAK are discussed. Structural Insight into concerted inhibition of alpha 2 beta 2-type aspartate kinase from Corynebacterium glutamicum.,Yoshida A, Tomita T, Kurihara T, Fushinobu S, Kuzuyama T, Nishiyama M J Mol Biol. 2007 Apr 27;368(2):521-36. Epub 2007 Feb 20. PMID:17350037[3] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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