Solution NMR Structure of the Gtpase Activating (GAP) Domain of Vope, A Vibrio Cholerae T3Ss Effector Protein

Abstract

Vibrio cholerae uses a type III secretion system to inject effector proteins into a host cell. Recently, a putative GTPase Activating Protein (GAP) called VopE was identified as a pathogenic protein that affected host mitochondrial dynamics and immune response. However, biophysical and structural characterization has been missing. We describe solution NMR structure of the putative GAP domain (73-204) of VopE. Using SEC-SAXS data, we improved the quality of the output calculated structures. Structural comparison with other ToxGAP's revealed a conserved overall fold with several unique features to VopE. By examining the conservation of residues at putative binding interface, we again find features conserved to all ToxGAP's and some only observed in VopE. Based on NMR data with its putative GTPase target, we hypothesize on other potential target mitochondrial GTPases.