The lysozymes encoded by bacteriophage T7 and K11 are both bifunctional enzymes sharing an extensive sequence homology (75%). The constructions of chimeric lysozymes were carried out by swapping the N-terminal and C-terminal domains between phage T7 and K11 lysozymes. This technique generated two chimeras, T7K11-lysozyme (N-terminal T7 domain and C-terminal K11 domain) and K11T7-lysozyme (N-terminal K11 domain and C-terminal T7 domain), which are both enzymatically active. The amidase activity of T7K11-lysozyme is comparable with the parental enzymes while K11T7-lysozyme exhibits an activity that is approximately 45% greater than the wild-type lysozymes. Moreover, these chimeric constructs have optimum pH of 7.2-7.4 similar to the parental lysozymes but exhibit greater thermal stabilities. On the other hand, the chimeras inhibit transcription comparable with the parental lysozymes depending on the source of their N-terminals. Taken together, our results indicated that domain swapping technique localizes the N-terminal region as the domain responsible for the transcription inhibition specificity of the wild type T7 and K11 lysozymes. Furthermore, we were able to develop a simple and rapid purification scheme in purifying both the wild-type and chimeric lysozymes.