COLQ encodes the subunit of a collagen-like molecule associated with acetylcholinesterase in skeletal muscle. Each molecule is composed of three identical subunits. Each subunit contains a proline-rich attachment domain (PRAD) that binds an acetylcholinesterase tetramer to anchor the catalytic subunit of the enzyme to the basal lamina. The cDNA encodes a deduced 455-amino acid protein with 89% homology to the rodent ColQ peptide. Conserved domains include a secretion signal peptide, a proline-rich attachment domain (PRAD) that interacts with AChE(T), 2 cysteines that form disulfide bonds with AChE(T), a collagen domain, conserved cysteines that stabilize the tripal helical domain, and proteoglycan binding domains that anchor the tripal helical domain to the basal lamina.