Laboratory of Microbial Technology, Division of Applied Molecular Microbiology and Biomass Chemistry, Department of Bioscience and Biotechnology, Faculty of Agriculture, Graduate School, Kyushu University, Hakozaki, Higashi-ku, Fukuoka, Japan.
Benef Microbes. 2012 Mar 1;3(1):3-12. doi: 10.3920/BM2011.0047.
Bacteriocins are antimicrobial peptides that are ribosomally synthesised by bacteria. Bacteriocins produced by Gram-positive bacteria, including lactic acid bacteria, are under focus as the next generation of safe natural biopreservatives and as therapeutic alternatives to antibiotics. Recently, two novel types of non-lantibiotic class II bacteriocins have been reported with unique characteristics in their structure and biosynthesis mechanism. One is a circular bacteriocin that contains a head-to-tail structure in the mature form, and the other is a leaderless bacteriocin without an N-terminal extension in the precursor peptide. A circular structure can provide the peptide with remarkable stability against various stresses; indeed, circular bacteriocins are known to possess higher stability than general linear bacteriocins. Leaderless bacteriocins are distinct from general bacteriocins, because they do not contain N-terminal leader sequences, which are responsible for the recognition process during secretion and for inactivation of bacteriocins inside producer cells. Leaderless bacteriocins do not require any post-translational processing for activity. These two novel types of bacteriocins are promising antimicrobial compounds, and their biosynthetic mechanisms are expected to be applied in synthetic biology to design new peptides and for new mass production systems. However, many questions remain about their biosynthesis. In this review, we introduce recent studies on these types of bacteriocins and their potential to open a new world of antimicrobial peptides.
细菌素是一类由细菌核糖体合成的抗菌肽。革兰氏阳性菌（包括乳酸菌）产生的细菌素作为下一代安全的天然生物防腐剂和抗生素的治疗替代品受到关注。最近，报道了两种新型的非类脂肽 II 型细菌素，它们在结构和生物合成机制上具有独特的特征。一种是具有成熟形式头尾结构的环状细菌素，另一种是前体肽中没有 N 端延伸的无领袖细菌素。环状结构可以为肽提供对各种应激的显著稳定性；事实上，已知环状细菌素比一般线性细菌素具有更高的稳定性。无领袖细菌素与一般细菌素不同，因为它们不包含负责分泌过程中识别和使产生细胞内细菌素失活的 N 端前导序列。无领袖细菌素不需要任何翻译后加工即可发挥活性。这两种新型细菌素是很有前途的抗菌化合物，它们的生物合成机制有望在合成生物学中应用于设计新的肽和新的大规模生产系统。然而，关于它们的生物合成仍存在许多问题。在这篇综述中，我们介绍了这些类型的细菌素的最新研究及其在开辟抗菌肽新世界方面的潜力。
