By use of a functional assay for activity, an autolysin structural gene was cloned on a 3 kb RI DNA fragment from a λgt11 expression library of 168 genomic DNA. Sequencing of the fragment showed five open reading frames, the central one of which encoded the lytic enzyme as found by subclone activity mapping and its homology to a recently sequenced autolysin gene. The protein had a deduced sequence of 272 amino acids and a molecular mass of 29957 Da. When expressed in DH5α, the protein was processed to a 21 kDa form, as estimated by renaturing SDS-PAGE. The autolysin was an -acetylmuramyl-L-alanine amidase and its activity was MgCl-dependent (20 mM optimum) and LiCl-sensitive. The enzyme could bind to and hydrolyse a wide range of peptidoglycan substrates isolated from Gram-positive bacteria; the binding was also MgCl-dependent. Initial mapping experiments located the autolysin gene near on the 168 chromosome.


Article metrics loading...

Loading full text...

Full text loading...

This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error