Amino-acid sequence and cell-adhesion activity of a fibril-forming collagen from the tube worm Riftia pachyptila living at deep sea hydrothermal vents.
We have determined the amino acid sequence of the alpha chain of a fibril-forming collagen from the body wall of the marine invertebrate Riftia pachyptila (vestimentifera) by Edman degradation. The pepsin-solubilized collagen chain consists of a 1011-residue triple-helical domain and short remnants of N- and C-telopeptides. The triple-helical sequence showed one imperfection of the collagen Gly-Xaa-Yaa triplet repeat structure due to a Gly-->Ala substitution. This imperfection is correlated to a prominent kink in the molecule observed by electron microscopy. No strong sequence similarity was found with the fibril-forming vertebrate collagen types I-III, V and XI except for the invariant Gly residues. However, one of the two consensus cross-linking sequences was well conserved. The Riftia collagen shared with the vertebrate collagens many post-translational modifications. About 50% of the Pro and Lys residues are found in the Yaa position and were extensively hydroxylated to 4-hydroxyproline (4Hyp) and hydroxylysine (Hyl). A few proline residues in Xaa position were partially hydroxylated to either 4Hyp or 3Hyp. Despite the low sequence similarity, Riftia collagen was a potent adhesion substrate for two human cell lines. Cell adhesion could be inhibited by antibodies against the integrin beta 1 subunit but not by RGD peptides. This biological activity is apparently conserved in fibril-forming collagens of distantly related species but does not require the two RGD sequences present in Riftia collagen.
Mann
K
K
Max-Planck-Institut für Biochemie, Martinsried, Federal Republic of Germany.
Gaill
F
F
Timpl
R
R
D000595:Amino Acid Sequence; D000818:Animals; D002448:Cell Adhesion; D015815:Cell Adhesion Molecules / Q000502:physiology; D003094:Collagen / Q000737:chemistry* / Q000235:genetics / Q000502:physiology; D003488:Cyanogen Bromide; D007448:Invertebrates; D046911:Macromolecular Substances; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000302:isolation & purification; D011499:Protein Processing, Post-Translational; D012623:Seawater
D015815:Cell Adhesion Molecules; D046911:Macromolecular Substances; D010446:Peptide Fragments; D003094:Collagen; D003488:Cyanogen Bromide