Crystal structures of TcTS indicate active site flexibility, in particular that Tyr119 of the acceptor binding site adopts two different orientations: an orientation of Tyr119 that allows it to stack with the acceptor ligand, described by a χ1 value of approximately −60°, and a downward-pointing orientation of Tyr119, essentially blocking the sialic acid binding site, with a χ1 value of 180°.
We show that the three Sp1 binding motifs can adopt different forms of G-quadruplex structure and that the Sp1 protein can recognize and bind to its site folded into a G-quadruplex.
Particularly, two of the three hot spot residues on IL-2 binding sites (Phe42 and Tyr45) adopt different side chain formations in the interfaces.
Importantly, the hinge-binding groups can adopt different functions in the KAc site, interacting either with Asn140, Pro82 or water molecules of the ZA channel.
Similarly, compounds 16 and 17 do not appear capable of making comparable interactions to those observed in X-ray structures suggesting that they might adopt different binding site poses related to these substitutions.
This substituent was located more external to the binding cavity and able to adopt different poses.
(C ) Ala Phe and Ala-Ala-Ala adopt different orientations within the binding site of PepTSt.
Recent crystal structures and functional data on a bacterial POT family transporter, PepTSt, a homologue of PepT1 and PepT2, revealed that peptides could adopt different orientations within the binding site.
The E- and Z-isomers adopt different binding modes when bound to mouse DHFR.
In order to demonstrate the unique ability of ProBiS to detect and align similar binding sites in the absence of fold similarity, we examined 10 pairs of protein structures, where the two members of a pair adopt different folds, but have a similar binding site and perform a similar function (Russell, 1998).
