Figure 1.

Molecular view of a sarcomere in vertebrate skeletal muscle. The sarcomere, adapted (with permission) from Mijailovich et al. (2019), highlights structures of a few of the β-sheet-containing domains within titin (red) and nebulin (violet). Top left: X-ray diffraction crystal structure of three contiguous Ig domains (I9-I11), a small portion of the I-band region of human titin (PDB accession no. 5JDD; Bogomolovas et al., 2016). Top right: Solution NMR structure of the SH3 domain from human nebulin (PDB accession no. 1NEB; Politou et al., 1998).