Cloning and identification of bacteriophage T4 gene 2 product gp2 and action of gp2 on infecting DNA in vivo.

We sequenced bacteriophage T4 genes 2 and 3 and the putative C-terminal portion of gene 50. They were found to have appropriate open reading frames directed counterclockwise on the T4 map. Mutations in genes 2 and 64 were shown to be in the same open reading frame, which we now call gene 2. This gene codes for a protein of 27,068 daltons. The open reading frame corresponding to gene 3 codes for a protein of 20,634 daltons. Appropriate bands on polyacrylamide gels were identified at 30 and 20 kilodaltons, respectively. We found that the product of the cloned gene 2 can protect T4 DNA double-stranded ends from exonuclease V action.