Fig. 1

Structure of AcrIE2. A Schematic representation of secondary structures in AcrIE2. Its amino acid sequence is shown and numbered below. B Crystal structure of AcrIE2 solved by single-wavelength anomalous diffraction. The structure is shown in rainbow format from the N-terminus (blue) to the C-terminus (red). N- and C-termini and secondary structures are also indicated. C Electrostatic potential surface (red = − 5.0 kT, blue = + 5.0 kT) of AcrIE2 in the same orientation as shown in B. The structures were displayed using the PyMOL software (The PyMOL Molecular Graphics System, Version 2.0 Schrödinger, LLC)