PqqL is flexible and adopts an elongated conformation in solution.

Small angle X-ray scattering of PqqL (A) and derived P(r) (B), Kratky (C) and Guinier (D) plots showing that PqqL adopts a highly elongated conformation in solution with a Dmax of 140 Å and has interdomain flexibility. (E) the simulated solution scattering of the PqqL crystal structure is a relatively poor fit for solution scattering data, suggesting that PqqL adopts multiple conformations in solution. (F) PqqL adopts different conformations in crystallo. The light blue ribbon represents PqqL in the refined crystal structure while the dark blue ribbon represents the position of PqqL domain 2 in the low-resolution crystal form shown in S7 Fig, illustrating the difference in domain orientation between to two crystal forms. The fit of this alternative conformation is shown (right).