HOLY PROTEINS .2. THE SOLUBLE LYTIC TRANSGLYCOSYLASE

Enzymes involved in the metabolism of the bacterial cell wall peptidog lycan are excellent targets for antibiotics. Penicillins and related b eta-lactam antibiotics inhibit the enzymes that act on the peptide cro ss-links of the peptidoglycan. The X-ray structure of the transglycosy lase revealed a two-layered ring of alpha-helices in a right-handed su perhelical arrangement with a separate catalytic domain on top, which resembles the fold of goose-type lysozyme. Three sequence motifs were found that characterize the catalytic and substrate-binding sites in t he enzyme. These motifs are present in a broad family of muramidases a nd chitinases.