"Tear down that wall"-a critical evaluation of bioinformatic resources available for lysin researchers

Lytic enzymes, or lysins for short, break down peptidoglycan and interrupt the continuity of the cell wall, which, in turn, causes osmotic lysis of the bacterium. Their ability to destroy bacteria from within makes them promising antimicrobial agents that can be used as alternatives or supplements to antibiotics. In this paper, we briefly summarize basic terms and concepts used to describe lysin sequences and delineate major lysin groups. More importantly, we describe the domain repertoire found in lysins and critically review bioinformatic tools or databases which are used in studies of these enzymes (with particular emphasis on the repositories of Hidden Markov models). Finally, we present a novel comprehensive, meticulously curated set of lysin-related family and domain models, sort them into clusters that reflect major families, and demonstrate that the selected models can be used to efficiently search for new lysins.