Fig. 1.

The utrophin ABD structure. (A and B) Ribbon diagrams of two different views of the UTR261 crystal structure 1QAG comprising a dimer with two molecules shown in red and blue. These are overlayed with the structure of α-actinin 1WKU to demonstrate the apparent two-dimensional domain swap. Annotation to CH1 and CH2 refer to the corresponding CH domains of the UTR261 structure and the α-actinin fit. (C and D) Images of utrophin monomers in the open conformation and closed conformation derived from the structure in (A) and (B). The position of threonine 36 and serine 241 are shown in yellow spacefill.