Open AccessStructural homology among calf thymus α-polymerase polypeptides
Author(s) -
Waltraud Albert,
Friedrich Grummt,
Ulrich Hübscher,
Samuel H. Wilson
Publication year - 1982
Publication title -
nucleic acids research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 9.008
H-Index - 537
eISSN - 1362-4954
pISSN - 0305-1048
DOI - 10.1093/nar/10.3.935
Subject(s) - biology , homology (biology) , microbiology and biotechnology , polymerase , gel electrophoresis , polymerase chain reaction , polyacrylamide gel electrophoresis , biochemistry , dna , gene , enzyme
A sample of highly purified calf thymus alpha-polymerase contained an abundant 118,000 Mr polypeptide as well as five lower molecular weight polypeptides in the range of 54,000- to 64,000-Mr. This 118,000-Mr polypeptide was capable of DNA polymerase activity, as revealed by in situ assay after SDS-polyacrylamide gel electrophoresis. Tryptic peptide mapping indicated that the 118,000-Mr polypeptide shared extensive primary structure homology with 57,000-, 58,000- and 64,000-Mr polypeptides and some limited homology with 54,000- and 56,000-Mr polypeptides. This is the first evidence that lower and higher Mr polypeptides of purified calf thymus alpha-polymerase share sequence homology; these results are interpreted in the context of a model that predicts the existence of a common precursor with molecular weight greater than 140,000.