Chemically-Rich Structure and Dynamics in the Active Site of Tryptophan Synthase
EMSL Project ID
51723
Abstract
Our goal is to understand the molecular basis for reaction specificity in pyridoxal-5'-phosphate (PLP) dependent enzymes, focusing on the 143 kDa, PLP-dependent enzyme tryptophan synthase (TS), mutants of TS, and related PLP-dependent enzymes. Our hypothesis is that for a given stereoelectronic environment, reaction specificity is determined by the specific protonation states on the cofactor and substrate and that these, in turn, are dictated by the surrounding active site side chain residues. To test this hypothesis we are working to describe – with atomic resolution – the transformation of substrate into product in the beta-subunit active site of tryptophan synthase; that is, we seek to specify the location of all atoms in the enzyme active site, including hydrogens. Realizing this goal relies on NMR crystallography – the synergistic combination of solid-state NMR, X-ray crystallography, and computational chemistry. As part of this work we are developing the spectroscopic and biochemical tools to measure isotropic and anisotropic chemical shift interactions for substrates and catalytic side chains within the active site. These are applied here to a TS mutant designed specifically to modify both the protonation states and the catalytic efficiency of the TS nanomachine.
Project Details
Project type
Limited Scope
Start Date
2020-10-28
End Date
2020-12-28
Status
Closed
Released Data Link
Team
Principal Investigator
Team Members