Genetic evidence for two protein domains and a potential new activity in bacteriophage T4 DNA polymerase

Genetics. 1990 Feb;124(2):213-20. doi: 10.1093/genetics/124.2.213.


Intragenic complementation was detected within the bacteriophage T4 DNA polymerase gene. Complementation was observed between specific amino (N)-terminal, temperature-sensitive (ts) mutator mutants and more carboxy (C)-terminal mutants lacking DNA polymerase polymerizing functions. Protein sequences surrounding N-terminal mutation sites are similar to sequences found in Escherichia coli ribonuclease H (RNase H) and in the 5'----3' exonuclease domain of E. coli DNA polymerase I. These observations suggest that T4 DNA polymerase, like E. coli DNA polymerase I, contains a discrete N-terminal domain.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Centrifugation, Density Gradient
  • DNA, Viral / biosynthesis
  • DNA, Viral / genetics
  • DNA-Directed DNA Polymerase / genetics*
  • DNA-Directed DNA Polymerase / metabolism
  • Genes, Viral*
  • Genetic Complementation Test
  • Molecular Sequence Data
  • Mutation
  • Sequence Homology, Nucleic Acid
  • T-Phages / enzymology
  • T-Phages / genetics*
  • Temperature


  • DNA, Viral
  • DNA-Directed DNA Polymerase