Secondary-structure switch regulates the substrate binding of a YopJ family acetyltransferase

Abstract

The Yersinia outer protein J (YopJ) family of effectors, which are present in many plant and animal pathogens are non-canonical acetyltransferases that are activated by the eukaryote-specific cofactor inositol hexaphosphate (InsP6). Here, the authors combine X-ray crystallography, biochemical and functional analyses to characterise the structure and activation mechanism of the YopJ family effector PopP2 from the plant pathogen Ralstonia solanacearum and observe that InsP6 binding induces major conformational changes in PopP2 with a helix-to-strand fold-switching in its catalytic core.