title: A conserved nucleotide sequence, coding for a segment of the C-propeptide, is found at the same location in different collagen genes.
abstract: The nucleotide sequence of a segment of the chick alpha 1 type III collagen gene which codes for the C-propeptide was determined and compared with the corresponding sequence in the alpha 1 type I and alpha 2 type I collagen genes. As in the alpha 2 type I gene the coding information for the C-propeptide of the type III collagen gene is subdivided in four exons. Similarly, the amino proximal exon contains sequences for both the carboxy terminal end of the alpha-helical segment of collagen and for the beginning of the C-propeptide in both genes. Therefore, this organization of exons must have been established before these two collagen genes arose by duplication of a common ancestor. In several subsegments the deduced amino acid sequence for the C-propeptide of type III collagen shows a strong homology with the corresponding amino acid sequence in alpha 1 and alpha 2 type I. For one of these homologous amino acid sequences, however, the nucleotide sequence is much better conserved than for the others. It is possible that a mechanism of gene conversion has maintained the homogeneity of this nucleotide sequence among the interstitial collagen genes. Alternatively, the conserved nucleotide sequence may represent a regulatory signal which could function either in the DNA or in the RNA.
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002645:Chickens; D003094:Collagen / Q000235:genetics*; D005796:Genes; D010446:Peptide Fragments
chemical_list: D010446:Peptide Fragments; D003094:Collagen