Evidence for Hysteretic Substrate Channeling in the Proline Dehydrogenaseand ∆¹-Pyrroline-5-carboxylate Dehydrogenase Coupled Reaction of Proline UtilizationA(PutA)

Authors

Michael A Moxley, University of Nebraska - Lincoln
Nikhilesh Sanyal, University of Nebraska-LincolnFollow
Navasona Krishnan, University of Nebraska - Lincoln
John J. Tanner, University of Missouri-Columbia, Columbia, MOFollow
Donald F. Becker, University of Nebraska-LincolnFollow

Date of this Version

2014

Citation

THE JOURNAL OF BIOLOGICAL CHEMISTRY VOL. 289, NO. 6, pp. 3639–3651, February 7, 2014

Comments

© 2014 by The American Society for Biochemistry and Molecular Biology, Inc.

Abstract

Background: PutA from Escherichia coli is a bifunctional enzyme and transcriptional repressor in proline catabolism.

Results: Steady-state and transient kinetic data revealed a mechanism in which the two enzymatic reactions are coupled by an activation step.

Conclusion: Substrate channeling in PutA exhibits hysteretic behavior.

Significance: This is the first kinetic model of bi-enzyme activity in PutA and reveals a novel mechanism of channeling activation.