Beveridge T J, Pouwels P H, Sára M, Kotiranta A, Lounatmaa K, Kari K, Kerosuo E, Haapasalo M, Egelseer E M, Schocher I, Sleytr U B, Morelli L, Callegari M L, Nomellini J F, Bingle W H, Smit J, Leibovitz E, Lemaire M, Miras I, Salamitou S, Béguin P, Ohayon H, Gounon P, Matuschek M, Koval S F
Department of Microbiology, College of Biological Science, University of Guelph, Canada.
FEMS Microbiol Rev. 1997 Jun;20(1-2):99-149. doi: 10.1111/j.1574-6976.1997.tb00305.x.
Although S-layers are being increasingly identified on Bacteria and Archaea, it is enigmatic that in most cases S-layer function continues to elude us. In a few instances, S-layers have been shown to be virulence factors on pathogens (e.g. Campylobacter fetus ssp. fetus and Aeromonas salmonicida), protective against Bdellovibrio, a depository for surface-exposed enzymes (e.g. Bacillus stearothermophilus), shape-determining agents (e.g. Thermoproteus tenax) and nucleation factors for fine-grain mineral development (e.g. Synechococcus GL 24). Yet, for the vast majority of S-layered bacteria, the natural function of these crystalline arrays continues to be evasive. The following review up-dates the functional basis of S-layers and describes such diverse topics as the effect of S-layers on the Gram stain, bacteriophage adsorption in lactobacilli, phagocytosis by human polymorphonuclear leukocytes, the adhesion of a high-molecular-mass amylase, outer membrane porosity, and the secretion of extracellular enzymes of Thermoanaerobacterium. In addition, the functional aspect of calcium on the Caulobacter S-layer is explained.
尽管在细菌和古菌中越来越多地发现了S层，但在大多数情况下，S层的功能仍然难以捉摸，这令人费解。在少数情况下，S层已被证明是病原体上的毒力因子（如胎儿弯曲杆菌胎儿亚种和气单胞菌杀鲑亚种），可抵御蛭弧菌，是表面暴露酶（如嗜热脂肪芽孢杆菌）的储存库、形状决定因子（如嗜热栖热菌）和细粒矿物发育的成核因子（如聚球藻GL 24）。然而，对于绝大多数具有S层的细菌来说，这些晶体阵列的自然功能仍然难以确定。以下综述更新了S层的功能基础，并描述了诸如S层对革兰氏染色的影响、噬菌体在乳酸杆菌中的吸附、人类多形核白细胞的吞噬作用、高分子量淀粉酶的粘附、外膜孔隙率以及嗜热厌氧菌胞外酶的分泌等不同主题。此外，还解释了钙对柄杆菌S层的功能作用。
