title: Tough tendons. Mussel byssus has collagen with silk-like domains.
abstract: The primary structure of the alpha-chain of preCol-D (molecular mass = 80 kDa), a tanned collagenous protein predominating in the distal portion of the byssal threads of the mussel Mytilus edulis, was deduced from cDNA to encode an unprecedented natural block copolymer with three major domain types: a central collagen domain flanked by fibroin-like domains and followed by histidine-rich termini. The fibroin-like domains have sequence motifs that strongly resemble the crystalline polyalanine-rich and amorphous glycine-rich regions of spider dragline silk fibroins. The terminal regions resemble the histidine-rich domains of a variety of metal-binding proteins. The silk domains may toughen the collagen by increasing its strength and extensibility. PreCol-D expression is limited to the mussel foot, which contains a longitudinal gradient of preCol-D mRNA. This gradient increases linearly in the proximal to distal direction and reaches a maximum just before the distal depression of the foot.
authors.affiliation: College of Marine Studies and Department of Chemistry and Biochemistry, University of Delaware, Newark, Delaware 19716, USA.
authors.forename: X X
authors.initials: XX
authors.lastname: Qin
authors.forename: K J
authors.initials: KJ
authors.lastname: Coyne
authors.forename: J H
authors.initials: JH
authors.lastname: Waite
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001704:Biopolymers; D049872:Bivalvia; D002851:Chromatography, High Pressure Liquid; D003094:Collagen / Q000737:chemistry* / Q000235:genetics; D018076:DNA, Complementary; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D011498:Protein Precursors / Q000737:chemistry / Q000235:genetics; D017386:Sequence Homology, Amino Acid
chemical_list: D001704:Biopolymers; D018076:DNA, Complementary; D011498:Protein Precursors; D003094:Collagen