The structure of AvrRxo1-ORF1 and its complex with the AvrRxo1-ORF2 chaperone (PDB id 4Z8V). (a) The AvrRxo1-ORF1 monomer consists of a major, middle α/β domain (helices are colored in magenta) and two flanking domains, whose helices are colored pink and violet, respectively. (b,c) The 1:1 complex of AvrRxo1-ORF1/AvrRxo1-ORF2 in two views, 180 degrees apart. AvrRxo1-ORF2 is shown in surface representation. (d) The 2:2 complex of AvrRxo1-ORF1/AvrRxo1-ORF2 in two views, 90 degrees apart. One dimer is gray and the other is colorful, consistent with colors in (a). AvrRxo1-ORF2 is shown in red cartoon.