Detection of putative new mutacins by bioinformatic analysis using available web tools

The increasing resistance of bacteria to antibiotics motives researches for new antimicrobial compounds [1]. In this way bacteriocins which are small antibacterial ribosomally synthetized peptides produced by bacteria represent promising candidates [2,3]. Bacteriocins acted on sensitive cells by punching pores in their membrane. To date, the bacteriocins produced by Gram positive bacteria are grouped in two major classes [4] but four classes are also proposed [5]. Lantibiotic_class I and non-lantibiotic_class II bacteriocins display great diversity with regard to their structures, modes of action, and genetic determinants [4,6]. Typical bacteriocin biosynthesis operons are usually organised as a cluster of genes comprising the prepropeptide coding gene associated with genes for exportation and maturation (ATP-binding cassette (ABC) transporter and sometimes combined to a specific protease), genes conferring immunity to the inhibitory activity to prevent self-killing and occasionally genes involved in regulation of the production of the bacteriocin [6,3]. The expression of the bacteriocin gene cluster is under the control of a two-component signal transduction system (TCS) composed of an histidine kinase (HK) and its associated response regulator (RR) that are usually part of the cluster. The inducer can be either the bacteriocin itself or a bacteriocin-like peptide [7].Discovery of new bacteriocins traditionally rest upon functionnal assays based on the inhibition of specific target bacteria. Such method is limited and time-consuming regarding the culture condition for bacteriocin production with the indicator strains used. The growing of genomic data makes the detection of new bacteriocin peptides possible by using an in silico screening strategy and precise computational analyses. Recently many research teams have bring to light existence of new type of bacteriocins using this strategy [8-11]. Furthermore, a very powerful tool for direct discovery of bacteriocins