Figure 2.
Sickle fiber structure. (A) Low-resolution structure of 14-stranded solid fiber determined by electron microscopy.46 Each HbS tetramer is represented as a sphere. (B) Atomic structure of deoxy-HbS determined by X-ray crystallography47 showing that 1 of the 2 β6 valines (purple) in each tetramer makes an intermolecular contact with an adjacent strand close to the pocket containing the hemes (orange). (C) Cross-section of sickle fiber composed of 7 double strands. (D) Cartoon of small molecule inhibitor that could fit into the shallow acceptor site for the β6 valine.
