Millisecond Timescale Motions Connect Amino Acid Interaction Networks in Alpha Tryptophan Synthase.

ABSTRACT: Tryptophan synthase is a model system for understanding allosteric regulation within enzyme complexes. Amino acid interaction networks were previously delineated in the isolated alpha subunit (αTS) in the absence of the beta subunit (βTS). The amino acid interaction networks were different between the ligand-free enzyme and the enzyme actively catalyzing turnover. Previous X-ray crystallography studies indicated only minor localized changes when ligands bind αTS, and so, structural changes alone could not explain the changes to the amino acid interaction networks. We hypothesized that the network changes could instead be related to changes in conformational dynamics. As such, we conducted nuclear magnetic resonance relaxation studies on different substrate- and products-bound complexes of

SUBMITTER: O'Rourke KF 

PROVIDER: S-EPMC6236060 | biostudies-literature | 2018

REPOSITORIES: biostudies-literature