3ab4
Crystal structure of feedback inhibition resistant mutant of aspartate kinase from Corynebacterium glutamicum in complex with lysine and threonineCrystal structure of feedback inhibition resistant mutant of aspartate kinase from Corynebacterium glutamicum in complex with lysine and threonine
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) is the first and committed enzyme of the biosynthetic pathway producing aspartate family amino acids, lysine, threonine, and methionine. AK from Corynebacterium glutamicum (CgAK), a bacterium used for industrial fermentation of amino acids, including glutamate and lysine, is inhibited by lysine and threonine in a concerted manner. To elucidate the mechanism of this unique regulation in CgAK, we determined the crystal structures in several forms: an inhibitory form complexed with both lysine and threonine, an active form complexed with only threonine, and a feedback inhibition-resistant mutant (S301F) complexed with both lysine and threonine. CgAK has a characteristic alpha(2)beta(2)-type heterotetrameric structure made up of two alpha subunits and two beta subunits. Comparison of the crystal structures between inhibitory and active forms revealed that binding inhibitors causes a conformational change to a closed inhibitory form, and the interaction between the catalytic domain in the alpha subunit and beta subunit (regulatory subunit) is a key event for stabilizing the inhibitory form. This study shows not only the first crystal structures of alpha(2)beta(2)-type AK but also the mechanism of concerted inhibition in CgAK. Mechanism of concerted inhibition of alpha2beta2-type hetero-oligomeric aspartate kinase from Corynebacterium glutamicum.,Yoshida A, Tomita T, Kuzuyama T, Nishiyama M J Biol Chem. 2010 Aug 27;285(35):27477-86. Epub 2010 Jun 23. PMID:20573952[3] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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