Uncoupling conformational states from activity in an allosteric enzyme

Research output: Contribution to journalArticle

Authors

  • João P Pisco
  • Cesira de Chiara
  • Kamila J Pacholarz
  • Acely Garza-Garcia
  • Roksana W Ogrodowicz
  • Philip A Walker
  • Perdita E Barran
  • Luiz Pedro S de Carvalho

Colleges, School and Institutes

External organisations

  • Mycobacterial Metabolism and Antibiotic Research Laboratory, The Francis Crick Institute, 1 Midland Road, London, NW1 1AT, UK.
  • Michael Barber Centre for Collaborative Mass Spectrometry, Manchester Institute of Biotechnology & School of Chemistry, University of Manchester, Manchester, M1 7DN, UK.
  • Structural Biology Science Technology Platform, The Francis Crick Institute, 1 Midland Road, London, NW1 1AT, UK.
  • Mycobacterial Metabolism and Antibiotic Research Laboratory, The Francis Crick Institute, 1 Midland Road, London, NW1 1AT, UK. luiz.carvalho@crick.ac.uk.

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.Active and inactive state ATP-phosphoribosyltransferases (ATP-PRTs) are believed to have different conformations. Here the authors show that in both states, ATP-PRT has a similar structural arrangement, suggesting that dynamic alterations are involved in ATP-PRT regulation by allosteric modulators.

Details

Original languageEnglish
Article number203
Number of pages10
JournalNature Communications
Volume8
Issue number1
Publication statusPublished - 7 Aug 2017

Keywords

  • ATP Phosphoribosyltransferase/chemistry, Adenosine Triphosphate/chemistry, Allosteric Regulation, Allosteric Site, Histidine/chemistry, Kinetics, Models, Molecular