Fig. 3
Structural flexibility. a Superimposition of the insert-in-flap (IF) domain for all molecules of the five full-length TtSlyD (TtSlyDFL) structures. Colored as in Fig. 2 except that the structurally most variable region is red (this region corresponds to the β8–β9 hairpin). b Superimposition of the FK506-binding protein (FKBP) domain for all eight TtSlyDFL structures and TtSlyD constructs with the insert-in-flap (IF) domain replaced by the flap loop from human FKBP12 (TtSlyDΔIF). Colored as in Fig. 2, except that residues 62–64, which can be considered as part of both the FKBP domain and the connector loops, are violet, and that the structurally most variable region is red (this region corresponds to the C-terminal tail). c All TtSlyDFL molecules of the five TtSlyDFL structures were superimposed on the inter-domain loops (except TtSlyDFL:FK506 molecule B, where the loops were uncharacteristically poorly defined in the electron density map). d A DynDom computational analysis was carried out to identify putative hinge regions between the domains based on pair-wise superimpositions of all possible combinations of TtSlyDFL molecules. The results are displayed in a “putty” representation: the more commonly a given residue was found to be part of a hinge region, the thicker the putty trace. For loop65–70, the thick part clearly converges around residues 62–64 at the N-terminal junction, while it is more diffusely distributed for loop118–125. Additional file 1 shows 1H–13C transverse relaxation optimized spectroscopy hetero single quantum coherence (TROSY-HSQC) spectra of the Fδ,ε/Yδ and Yε region data that corroborate the results from the DynDom analysis