Uncoupling conformational states from activity in an allosteric enzyme

DOI: 10.1038/s41467-017-00224-0

Authors: Joao P. Pisco (The Francis Crick Institute (Midland Road)) , Cesira De Chiara (The Francis Crick Institute) , Kamila J. Pacholarz (Manchester Institute of Biotechnology & School of Chemistry, University of Manchester) , Acely Garza-garcia (The Francis Crick Institute) , Roksana W. Ogrodowicz (The Francis Crick Institute) , Philip A. Walker (The Francis Crick Institute) , Perdita E. Barran (Manchester Institute of Biotechnology & School of Chemistry, University of Manchester) , Stephen J. Smerdon (The Francis Crick Institute) , Luiz Pedro S. De Carvalho (The Francis Crick Institute)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Nature Communications , VOL 8

State: Published (Approved)
Published: August 2017
Diamond Proposal Number(s): 7707 , 9826

Abstract: ATP-phosphoribosyltransferase (ATP-PRT) is a hexameric enzyme in conformational equilibrium between an open and seemingly active state and a closed and presumably inhibited form. The structure-function relationship of allosteric regulation in this system is still not fully understood. Here, we develop a screening strategy for modulators of ATP-PRT and identify 3-(2-thienyl)-l-alanine (TIH) as an allosteric activator of this enzyme. Kinetic analysis reveals co-occupancy of the allosteric sites by TIH and l-histidine. Crystallographic and native ion-mobility mass spectrometry data show that the TIH-bound activated form of the enzyme closely resembles the inhibited l-histidine-bound closed conformation, revealing the uncoupling between ATP-PRT open and closed conformations and its functional state. These findings suggest that dynamic processes are responsible for ATP-PRT allosteric regulation and that similar mechanisms might also be found in other enzymes bearing a ferredoxin-like allosteric domain.

Journal Keywords: Enzymes; Screening; Transferases; X-ray crystallography

Subject Areas: Biology and Bio-materials, Chemistry


Instruments: I04-Macromolecular Crystallography

Documents:
s41467-017-00224-0.pdf