Show simple item record Bansal, Akanksha Karanth, N. Megha Demeler, Borries Schindelin, Hermann Sarma, Siddhartha P. 2021-08-24T16:25:15Z 2021-08-24T16:25:15Z 2019
dc.identifier.citation Bansal, A., Karanth, N. M., Demeler, B., Schindelin, H., & Sarma, S. P. (2019). Crystallographic structures of IlvN·Val/Ile complexes: Conformational selectivity for feedback inhibition of aceto hydroxy acid synthases. Biochemistry, 58(15), 1992-2008. en_US
dc.description Accepted author manuscript en_US
dc.description.abstract Conformational factors that predicate selectivity for valine or isoleucine binding to IlvN leading to the regulation of aceto hydroxy acid synthase I (AHAS I) of Escherichia coli have been determined for the first time from high-resolution (1.9–2.43 Å) crystal structures of IlvN·Val and IlvN·Ile complexes. The valine and isoleucine ligand binding pockets are located at the dimer interface. In the IlvN·Ile complex, among residues in the binding pocket, the side chain of Cys43 is 2-fold disordered (χ1 angles of gauche– and trans). Only one conformation can be observed for the identical residue in the IlvN·Val complexes. In a reversal, the side chain of His53, located at the surface of the protein, exhibits two conformations in the IlvN·Val complex. The concerted conformational switch in the side chains of Cys43 and His53 may play an important role in the regulation of the AHAS I holoenzyme activity. A significant result is the establishment of the subunit composition in the AHAS I holoenzyme by analytical ultracentrifugation. Solution nuclear magnetic resonance and analytical ultracentrifugation experiments have also provided important insights into the hydrodynamic properties of IlvN in the ligand-free and -bound states. The structural and biophysical data unequivocally establish the molecular basis for differential binding of the ligands to IlvN and a rationale for the resistance of IlvM to feedback inhibition by the branched-chain amino acids. en_US
dc.language.iso en_US en_US
dc.publisher American Chemical Society en_US
dc.subject Crystal structure en_US
dc.subject.lcsh Peptides
dc.subject.lcsh Proteins
dc.subject.lcsh Ligands
dc.subject.lcsh Monomers
dc.subject.lcsh Molecules
dc.title Crystallographic structures of IlvN·Val/Ile complexes: Conformational selectivity for feedback inhibition of aceto hydroxy acid synthases en_US
dc.type Article en_US
dc.publisher.faculty Arts and Science en_US
dc.publisher.department Department of Chemistry and Biochemistry en_US
dc.description.peer-review Yes en_US
dc.publisher.institution Indian Institute of Science, Bangalore en_US
dc.publisher.institution University of Texas Health Science Center at San Antonio en_US
dc.publisher.institution University of Weurzburg en_US
dc.publisher.institution University of Lethbridge en_US
dc.publisher.url en_US

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