Construction and characterization of a 2.5-kilobase procollagen clone

Recombinant bacterial plasmids have been constructed by inserting double-stranded chicken procollagen cDNA sequences linked to chemically synthesized decanucleotides containing HindIII sites into the HindIII site of pBR322. After transformation of Escherichia coli chi1776, colonies were selected by ampicillin resistance and recombinants containing procollagen sequences were identified by colony hybridization to 32P-labeled procollagen cDNA. The inserts from three recombinant plasmids, pCg10, pCg13, and pCg45, were 1200, 2200, and 2550 base pairs long respectively. Their sequence homology has been established by restriction mapping and crosshybridization of nick-translated plasmids to Southern blots of Hpa II fragments of the inserts, pCg45 has been positively identified as containing the pro alpha2 collagen sequence by partial determination of the DNA sequence of its ends: it has a short thymine-rich sequence at one end and a sequence coding for residues 478--499 in the chicken alpha2 chain at the other end.