Ng Sandy Y M, Chaban Bonnie, VanDyke David J, Jarrell Ken F
Department of Microbiology and Immunology, Queen's University, Kingston, ON K7L 3N6, Canada.
Microbiology (Reading). 2007 Feb;153(Pt 2):305-14. doi: 10.1099/mic.0.2006/003087-0.
Signal peptidases are vital enzymes in the protein secretion pathway. In Archaea, type I signal peptidase, responsible for the cleavage of secretory signal peptides from the majority of secreted proteins, and prepilin peptidase-like signal peptidase, responsible for processing signal peptides from prepilin-like proteins like the preflagellins and various sugar-binding proteins, have been identified. In addition, the archaeal signal peptide peptidase, responsible for degradation of signal peptides after their removal from precursor proteins, has been characterized. These enzymes seem to have a mosaic of eukaryal and bacterial characteristics, and also possess unique archaeal traits. In this review, the most current knowledge with regard to these enzymes is summarized, including their cellular function, catalytic mechanism and distribution and conservation among archaeal species. Comparisons are drawn of these enzymes to their bacterial and eukaryal counterparts, and unique archaeal features highlighted.
信号肽酶是蛋白质分泌途径中的重要酶类。在古菌中，已鉴定出I型信号肽酶，它负责从大多数分泌蛋白中切割分泌信号肽；还有类前鞭毛蛋白肽酶样信号肽酶，它负责处理来自前鞭毛蛋白样蛋白（如前鞭毛蛋白和各种糖结合蛋白）的信号肽。此外，古菌信号肽肽酶也已得到表征，它负责信号肽从前体蛋白上切除后对其进行降解。这些酶似乎具有真核生物和细菌特征的镶嵌组合，同时也拥有独特的古菌特性。在本综述中，总结了关于这些酶的最新知识，包括它们的细胞功能、催化机制以及在古菌物种中的分布和保守性。还将这些酶与其细菌和真核生物对应物进行了比较，并突出了独特的古菌特征。
