Timing and Reset Mechanism of GTP Hydrolysis-Driven Conformational Changes of Atlastin Academic Article uri icon

Overview

MeSH Major

  • Elasticity
  • Gramicidin
  • Lipid Bilayers
  • Molecular Dynamics Simulation

abstract

  • The endoplasmic reticulum (ER) forms a branched, dynamic membrane tubule network that is vital for cellular function. Branching arises from membrane fusion facilitated by the GTPase atlastin (ATL). Many metazoan genomes encode for three ATL isoforms that appear to fulfill partially redundant function despite differences in their intrinsic GTPase activity and localization within the ER; however, the underlying mechanistic differences between the isoforms are poorly understood. Here, we identify discrete temporal steps in the catalytic cycle for the two most dissimilar isoforms, ATL1 and ATL3, revealing an overall conserved progression of molecular events from nucleotide binding and hydrolysis to ATL dimerization and phosphate release. A crystal structure of ATL3 suggests a mechanism for the displacement of the catalytic Mg(2+) ion following guanosine triphosphate (GTP) hydrolysis. Together, the data extend the mechanistic framework for how GTP hydrolysis drives conformational changes in ATL and how the cycle is reset for subsequent rounds of catalysis.

publication date

  • February 2, 2017

Research

keywords

  • Academic Article

Identity

Language

  • eng

PubMed Central ID

  • PMC5516944

Digital Object Identifier (DOI)

  • 10.1016/j.str.2017.05.007

PubMed ID

  • 28602821

Additional Document Info

start page

  • 997

end page

  • 1010.e4