Cloning and expression of a mureinolytic enzyme from the mycobacteriophage TM4

In this study, we describe the characterization, cloning, expression and purification of the lysin A gene of the mycobacteriophage TM4. The gene TM4_gp29 (gp29) is a 1644-bp gene that codes for a 58.6-kDa protein and contains peptidoglycan recognition protein, Zn-binding and amidase catalytic domains. The gene was cloned into Escherichia coli using the 'His-Tag' pQE60 vector. After affinity chromatography-mediated purification, the protein was concentrated and visualized using sodium dodecyl sulphate polyacrylamide gel electrophoresis. Evidence of peptidoglycan-degrading activity was observed initially by a chloroform assay and later by conventional zymogram analysis.