Fig. 2

Comparison of AcrIE2 structures determined by different techniques. A Cα-trace superposition of three AcrIE2 structures. Our crystal structure (PDB ID: 8HEK) is superimposed with one of the low-energy structures determined by NMR (PDB ID: 7KIX) and the previous crystal structure solved by ab initio phasing (PDB ID: 7CHQ). The three structures align well except for the loop connecting β4 and β5. Orientation of the superimposed structures is approximately identical to that shown in Fig. 1B. B Residual flexibility analyses of AcrIE2 structures. Average crystallographic B-factors of main chain atoms and average RMSD values of Cα atoms from NMR structure ensembles are shown as a function of residue number. Secondary structures of our AcrIE2 structure are also indicated