second calponin homology (CH) domain found in spectrin beta chain, non-erythrocytic 5 (SPTBN5) and similar proteins
Spectrin is an actin crosslinking and molecular scaffold protein that links the plasma membrane to the actin cytoskeleton, and functions in the determination of cell shape, arrangement of transmembrane proteins, and organization of organelles. It is composed of two antiparallel dimers of alpha- and beta- subunits. SPTBN5, also called beta-V spectrin, is a mammalian ortholog of Drosophila beta H spectrin that may play a crucial role as a longer actin-membrane cross-linker or to fulfill the need for greater extensible flexibility than can be provided by the other smaller conventional spectrins. SPTBN5 contains two copies of the CH domain. This model corresponds to the second CH domain. CH domains are actin filament (F-actin) binding motifs.