Abstract
The Yersinia outer protein J (YopJ) family effectors are widely deployed through the type III secretion system by both plant and animal pathogens. As non-canonical acetyltransferases, the enzymatic activities of YopJ family effectors are allosterically activated by the eukaryote-specific ligand inositol hexaphosphate (InsP6). However, the underpinning molecular mechanism remains undefined. Here we present the crystal structure of apo-PopP2, a YopJ family member secreted by the plant pathogen Ralstonia solanacearum. Structural comparison of apo-PopP2 with the InsP6-bound PopP2 reveals a substantial conformational readjustment centered in the substrate-binding site. Combining biochemical and computational analyses, we further identify a mechanism by which the association of InsP6 with PopP2 induces an α-helix-to-β-strand transition in the catalytic core, resulting in stabilization of the substrate recognition helix in the target protein binding site. Together, our study uncovers the molecular basis governing InsP6-mediated allosteric regulation of YopJ family acetyltransferases and further expands the paradigm of fold-switching proteins.
© 2021. The Author(s).
Publication types
-
Research Support, Non-U.S. Gov't
MeSH terms
-
Acetyltransferases / chemistry*
-
Acetyltransferases / genetics
-
Acetyltransferases / metabolism
-
Allosteric Regulation
-
Apoproteins / chemistry*
-
Apoproteins / genetics
-
Apoproteins / metabolism
-
Arabidopsis / microbiology*
-
Arabidopsis Proteins / chemistry
-
Arabidopsis Proteins / genetics
-
Arabidopsis Proteins / metabolism
-
Bacterial Proteins / chemistry*
-
Bacterial Proteins / genetics
-
Bacterial Proteins / metabolism
-
Catalytic Domain
-
Cloning, Molecular
-
Crystallography, X-Ray
-
Escherichia coli / genetics
-
Escherichia coli / metabolism
-
Gene Expression
-
Genetic Vectors / chemistry
-
Genetic Vectors / metabolism
-
Models, Molecular
-
Nicotiana / microbiology
-
Phytic Acid / chemistry*
-
Phytic Acid / metabolism
-
Protein Binding
-
Protein Conformation, alpha-Helical
-
Protein Conformation, beta-Strand
-
Protein Interaction Domains and Motifs
-
Ralstonia solanacearum / chemistry*
-
Ralstonia solanacearum / enzymology
-
Recombinant Fusion Proteins / chemistry
-
Recombinant Fusion Proteins / genetics
-
Recombinant Fusion Proteins / metabolism
-
Substrate Specificity
Substances
-
Apoproteins
-
Arabidopsis Proteins
-
Bacterial Proteins
-
RRS1 protein, Arabidopsis
-
Recombinant Fusion Proteins
-
YopP protein, Yersinia
-
Phytic Acid
-
Acetyltransferases