Comparison of holo- (a, in pink) and loaded-ArCP (c, in blue) in complex with an
adenylation domain in AT conformation (in white). The original structure of
EntB-ArCP (brown) in complex with EntE is shown in b) (2ROG). In b), EntB-ArCP sidechains
colored in red highlight interactions between A(N) and α2, those in blue show
interactions between A(C) and ArCP, and those in green denote interactions between A(C)
and loop1. The same color scheme was used for side-chains of EntE that are displayed in
a–c). d) Detail showcasing changes in the conformation of loop1. The orientation
in d is obtained by rotation of 30° around the Y vertical axis.