Cloning and expression of genes for lysozyme and a 20-kDal protein of colitis bacteriophage.

BamHI fragments of colitis phage DNA were cloned in pBR322 DNA, and the recombinant clones carrying the lysozyme gene were identified by lysozyme activity. The inserted DNA was 1.2 kb long and when expressed in minicells it produced lysozyme and a 20-kDal protein. Colitis-phage-specific mRNAs which hybridized to the insert were 0.5 kb and 0.7 kb long and were translated into lysozyme and a 20-kDal protein, respectively, in a cell-free system derived from rice embryos. They were transcribed as monocistronic mRNAs using the internal promoters present on the inserted DNA.