Isolation and sequence of a rat chymotrypsin B gene

G. I. Bell, C. Quinto, M. Quiroga, P. Valenzuela, C. S. Craik, W. J. Rutter

Research output: Contribution to journalArticlepeer-review

107 Citations (Scopus)


A cDNA clone encoding part of chymotrypsin B was isolated from a cDNA library prepared from rat pancreatic mRNA and used as a probe to isolate the chymotrypsin B gene. The nucleotide sequence of this gene is presented. The 4709-base pair transcribed portion of the isolated gene was inferred from the cDNA and gene sequence, and the 5' border was determined by primer extension on pancreatic polyadenylated RNA. The coding portion of the gene is interrupted by six introns. The active site residues His 57, Asp 102, and Ser 195 are encoded by separate exons. Moreover, two regions of the enzyme which form the substrate-binding pocket are also encoded by separate exons. Thus, the substrate specificity and catalytic activity of the enzyme are produced by joining several exons encoding protein segments that are intrinsically catalytically inactive. The number and location of the intron/exon junctions of the chymotrypsin gene as compared to those of other serine protease genes, as well as the location of the genes on separate chromosomes, suggest that the duplication that resulted in the formation of the chymotrypsin gene was an ancient evolutionary event.

Original languageEnglish
Pages (from-to)14265-14270
Number of pages6
JournalJournal of Biological Chemistry
Issue number22
Publication statusPublished - 1984

ASJC Scopus subject areas

  • Biochemistry


Dive into the research topics of 'Isolation and sequence of a rat chymotrypsin B gene'. Together they form a unique fingerprint.

Cite this