Immunoglobulin (Ig)-like domain of human titin C terminus and similar domains
Ig_Titin_like: domain similar to the M5, fifth immunoglobulin (Ig)-like domain from the human titin C terminus. Titin (also called connectin) is a fibrous sarcomeric protein specifically found in vertebrate striated muscle. Titin is gigantic; depending on isoform composition it ranges from 2970 to 3700 kDa, and is of a length that spans half a sarcomere. Titin largely consists of multiple repeats of Ig-like and fibronectin type 3 (FN-III)-like domains. Titin connects the ends of myosin thick filaments to Z disks and extends along the thick filament to the H zone, and appears to function similar to an elastic band, keeping the myosin filaments centered in the sarcomere during muscle contraction or stretching.