Phage P22 lysis genes: nucleotide sequences and functional relationships with T4 and lambda genes.

Wild-type and amber mutant alleles of the lysis genes of P22 were cloned and sequenced. Gene 13 encodes an 11,520-Da basic hydrophobic protein that has 89% amino acid homology to lambda S protein. Gene 19 encodes a protein that has a small degree of amino acid homology with T4 lysozyme, but we could detect no homology to lambda R or RZ proteins. The protein product of gene 19 was purified; its amino terminal amino acid sequence is as predicted by the DNA sequence. It starts with a single amino terminal methionine residue and is a basic protein with a molecular weight of 15,968. Plasmids expressing P22 gene 19, lambda genes R and RZ, and T4 gene e were constructed. All of these plasmids were able to complement both lambda R- and P22 19-.