Novel amino-terminal propeptide configuration in a fibrillar procollagen undergoing alternative splicing.
We isolated overlapping cDNAs from embryonic libraries of the sea urchin Strongylocentrotus purpuratus coding for a fibrillar procollagen (2 alpha chain) with a predicted molecular mass of about 320 kDa. The deduced primary structure of the echinoid chain consists of a 265-amino acid carboxyl-propeptide, a triple helical domain made of 337 uninterrupted Gly-X-Y repeats, and an unusually long amino-propeptide. Aside from a 10-cysteine globular region, a collagenous sequence, and a nonhelical segment, this protein domain includes a novel 4-cysteine motif repeated several times. Interestingly, preliminary evidence indicates that different combinations of the 4-cysteine repeats are encoded by alternatively spliced transcripts. Irrespective of this, the sea urchin 2 alpha procollagen chain represents the longest fibrillar molecule identified to date by cDNA cloning experiments in both vertebrate and invertebrate organisms.
Exposito
J Y
JY
Brookdale Center for Molecular Biology, Mt. Sinai School of Medicine, New York, New York 10029.
D'Alessio
M
M
Ramirez
F
F
D000595:Amino Acid Sequence; D000818:Animals; D003001:Cloning, Molecular; D004247:DNA / Q000235:genetics / Q000302:isolation & purification; D004625:Embryo, Nonmammalian / Q000502:physiology; D015723:Gene Library; D006801:Humans; D046911:Macromolecular Substances; D008969:Molecular Sequence Data; D011061:Poly A / Q000235:genetics / Q000302:isolation & purification; D011347:Procollagen / Q000235:genetics*; D011487:Protein Conformation; D012313:RNA / Q000235:genetics / Q000302:isolation & purification; D012326:RNA Splicing; D012333:RNA, Messenger; D015183:Restriction Mapping; D012617:Sea Urchins / Q000196:embryology / Q000235:genetics; D012689:Sequence Homology, Nucleic Acid
D046911:Macromolecular Substances; D011347:Procollagen; D012333:RNA, Messenger; D011061:Poly A; D012313:RNA; D004247:DNA