On the roles of substrate binding and hinge unfolding in conformational changes of adenylate kinase

Jason B. Brokaw, Jhih-Wei Chu*

*Corresponding author for this work

Research output: Contribution to journalArticle

35 Scopus citations

Abstract

We characterized the conformational change of adenylate kinase (AK) between open and closed forms by conducting five all-atom molecular-dynamics simulations, each of 100 ns duration. Different initial structures and substrate binding configurations were used to probe the pathways of AK conformational change in explicit solvent, and no bias potential was applied. A complete closed-to-open and a partial open-to-closed transition were observed, demonstrating the direct impact of substrate-mediated interactions on shifting protein conformation. The sampled configurations suggest two possible pathways for connecting the open and closed structures of AK, affirming the prediction made based on available x-ray structures and earlier works of coarse-grained modeling. The trajectories of the all-atom molecular-dynamics simulations revealed the complexity of protein dynamics and the coupling between different domains during conformational change. Calculations of solvent density and density fluctuations surrounding AK did not show prominent variation during the transition between closed and open forms. Finally, we characterized the effects of local unfolding of an important hinge near Pro177 on the closed-to-open transition of AK and identified a novel mechanism by which hinge unfolding modulates protein conformational change. The local unfolding of Pro177 hinge induces alternative tertiary contacts that stabilize the closed structure and prevent the opening transition.

Original languageEnglish
Pages (from-to)3420-3429
Number of pages10
JournalBiophysical Journal
Volume99
Issue number10
DOIs
StatePublished - 17 Nov 2010

Fingerprint Dive into the research topics of 'On the roles of substrate binding and hinge unfolding in conformational changes of adenylate kinase'. Together they form a unique fingerprint.

  • Cite this