Campus Units

Chemistry

Document Type

Article

Publication Version

Published Version

Publication Date

8-4-2015

Journal or Book Title

Proceedings of the National Academy of Sciences of the United States of America

Volume

112

Issue

37

First Page

11565

Last Page

11570

DOI

10.1073/pnas.1515366112

Abstract

Abstract

Enzyme I (EI) is the first component in the bacterial phosphotransferase system, a signal transduction pathway in which phosphoryl transfer through a series of bimolecular protein–protein interactions is coupled to sugar transport across the membrane. EI is a multidomain, 128-kDa homodimer that has been shown to exist in two conformational states related to one another by two large (50–90°) rigid body domain reorientations. The open conformation of apo EI allows phosphoryl transfer from His189 located in the N-terminal domain α/β (EINα/β) subdomain to the downstream protein partner bound to the EINα subdomain. The closed conformation, observed in a trapped phosphoryl transfer intermediate, brings the EINα/β subdomain into close proximity to the C-terminal dimerization domain (EIC), thereby permitting in-line phosphoryl transfer from phosphoenolpyruvate (PEP) bound to EIC to His189. Here, we investigate the solution conformation of a complex of an active site mutant of EI (H189A) with PEP. Simulated annealing refinement driven simultaneously by solution small angle X-ray scattering and NMR residual dipolar coupling data demonstrates unambiguously that the EI(H189A)–PEP complex exists in a dynamic equilibrium between two approximately equally populated conformational states, one corresponding to the closed structure and the other to a partially closed species. The latter likely represents an intermediate in the open-to-closed transition

Comments

This is an article from Venditti, Vincenzo, Charles D. Schwieters, Alexander Grishaev, and G. Marius Clore. "Dynamic equilibrium between closed and partially closed states of the bacterial Enzyme I unveiled by solution NMR and X-ray scattering." Proceedings of the National Academy of Sciences 112, no. 37 (2015): 11565-11570. doi: 10.1073/pnas.1515366112. Posted with permission.

Rights

Works produced by employees of the U.S. Government as part of their official duties are not copyrighted within the U.S. The content of this document is not copyrighted.

Language

en

File Format

application/pdf

Included in

Chemistry Commons

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