Amino acid sequence of the triple-helical domain of human collagen type VI.
The complete amino acid sequence of the triple-helical domain of human collagen VI was deduced from sequences of appropriate cDNA clones and confirmed to about 50% by Edman degradation of tryptic peptides. This domain consists of three different peptide segments containing some 335-336 amino acid residues originating from central portions of the alpha 1 (VI), alpha 2(VI), and alpha 3(VI) chains, respectively. Sequence identity in the X/Y positions of the Gly-X-Y repeats is rather low (10-15%) between the chains. Peculiar features of these sequences include 3 cysteine residues about 50 (alpha 3(VI)) and 89 (alpha 1(VI), alpha 2(VI)) residues away from the N-terminus and several Gly-X-Y interruptions clustered in the C-terminal two-thirds of the triple helix. These structures are presumably required for cross-linking collagen VI oligomers and for super-coiling of triple helices in the dimers. Other features include 11 Arg-Gly-Asp sequences, some of which are likely to be used as cell-binding sites, and four Asn-X-Thr sequences, allowing N-linked glycosylation along the triple helix. Junctional areas close to the helix contain short, cysteine-rich segments which may seal the triple-helical domain through disulfide bond formation, endowing it with high stability. These features, together with a low sequence homology to fiber-forming and basement-membrane collagens, document the unique character of collagen VI, whose triple helix is specifically adjusted for forming microfibrils in tissues.
Chu
M L
ML
Department of Biochemistry, Jefferson Institute of Molecular Medicine, Thomas Jefferson University, Philadelphia, Pennsylvania 19107.
Conway
D
D
Pan
T C
TC
Baldwin
C
C
Mann
K
K
Deutzmann
R
R
Timpl
R
R
D000595:Amino Acid Sequence; D001483:Base Sequence; D003001:Cloning, Molecular; D003094:Collagen / Q000032:analysis*; D004247:DNA / Q000032:analysis; D006801:Humans; D008969:Molecular Sequence Data; D011487:Protein Conformation
D003094:Collagen; D004247:DNA