ABSTRACT

Because the majority of bacterial species divide by binary fission, and do not have distinguishable somatic and germline cells, they could be considered to be immortal. However, bacteria ‘age’ due to damage to vital cell components such as DNA and proteins. DNA damage can often be repaired using efficient DNA repair mechanisms. However, many proteins have a functional ‘shelf life’; some are short lived, while others are relatively stable. Specific degradation processes are built into the life span of proteins whose activities are required to fulfil a specific function during a prescribed period of time (e.g. cell cycle, differentiation process, stress response). In addition, proteins that are irreparably damaged or that have come to the end of their functional life span need to be removed by quality control proteases. Other proteases are involved in performing a variety of specific functions that can be broadly divided into three categories: processing, regulation and feeding. This review presents a systematic account of the proteases of Bacillus subtilis and their activities. It reviews the proteases found in, or associated with, the cytoplasm, the cell membrane, the cell wall and the external milieu. Where known, the impacts of the deletion of particular proteases are discussed, particularly in relation to industrial applications.

中文翻译：

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芽孢杆菌蛋白酶的来龙去脉：活性、功能和商业意义

摘要

由于大多数细菌物种通过二元裂变分裂，并且没有可区分的体细胞和生殖细胞，因此它们可以被认为是永生的。然而，由于对重要的细胞成分（如 DNA 和蛋白质）的破坏，细菌会“老化”。DNA 损伤通常可以使用有效的 DNA 修复机制进行修复。然而，许多蛋白质具有功能性“保质期”。有些是短暂的，而有些则相对稳定。特定的降解过程构建在蛋白质的生命周期中，蛋白质的活性需要在规定的时间段内实现特定的功能（例如细胞周期、分化过程、应激反应）。此外，无法修复的损坏或功能寿命已到尽头的蛋白质需要通过质量控制蛋白酶去除。其他蛋白酶参与执行多种特定功能，可大致分为三类：加工、调节和喂养。本综述系统地介绍了枯草芽孢杆菌及其活性。它回顾了在细胞质、细胞膜、细胞壁和外部环境中发现或与之相关的蛋白酶。在已知的情况下，讨论了删除特定蛋白酶的影响，特别是在工业应用方面。