Bacteriocins classification

Most antimicrobial peptides produced by Gram-positive bacteria are classified as bacteriocins, and like microcins they are diverse in size and structure.35 36 Recent classification schemes divide bacteriocins into three classes lantibiotics (class I), heat-stable non-lantibiotics (class II) and heat-labile antimicrobial proteins (class III), of which the majority of bacteriocins belong either to class I or class II. NMR spectroscopy has been applied in numerous studies of bacteriocins and an overview of the range of diversity in the 3D structures that have been determined by NMR spectroscopy is provided in Figure 4. 

A fourth class, proposed by Klaenhammer [21] is rather questionable. This class comprised the complex bacteriocins, composed of protein plus one or more chemical moieties (lipid, carbohydrate) required for activity plantaricin S, leuconocin S, lactocin 27, pediocin SJ-1 [57-61]. The existence of this fourth class was supported by the observation that some bacteriocin activities were destroyed by glycolytic and lipolytic enzymes [60]. However, such bacteriocins have not yet been characterized adequately at the biochemical level and the recognition of this class therefore seems to be premature. The class IIC of the Klaenhammer [21] classification has recently been shown not to exist. 

Rgure 5.1. Classification scheme of the bacteriocins of Gram (+) bacteria, revised from Cotter et al. (2005b). The main distinction is made between the Class I lantibiotics, which undergo extensive post-translational modifications, and the Class II non-modified bacteriocins. The amino acid sequence and structural features of one example bacteriocin of each different class are shown. 

Rea, M., Ross, R.F., Cotter, R, and Hill, C. (2011a). Classification of Bacteriocins from gram-positive bacteria. In Prokaryotic Antimicrobial Peptides ((eds) D.Drider and S. Rebuffat) Springer, New York, 29-53. 

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