Van den Bussche R A, Lyon J D, Bohach G A
Department of Biological Sciences, University of Idaho, Moscow 83843.
Mol Phylogenet Evol. 1993 Dec;2(4):281-92. doi: 10.1006/mpev.1993.1027.
The pyrogenic toxin (PT) family is composed of the staphylococcal enterotoxins (SE), the toxic shock syndrome toxin, and the streptococcal pyrogenic exotoxins (SPE). Whereas considerable effort has focused on characterization of PTs due to their unique biological properties, our understanding of the evolution of this gene family is incomplete. Phylogenetic relationships for members of the PT family were estimated by examining the previously reported nucleotide sequences of the genes encoding SPEA, SPEC, SEA, SEB, SEC1, SEC2, SEC3, SED, and SEE. Additionally, we present and analyze sequence data on seven previously unreported sec genes. Within the PT family, sequence divergence was partitioned in a hierarchical fashion such that mean sequence divergence ranged from 1.179 among all 16 toxin genes, 0.443 among those restricted to Staphylococcus, and 0.028 among the genes encoding 10 variants of Type C SE. Results of this study are interpreted as suggesting that the PT family consists of two large clades. One clade consists of the staphylococcal toxins SEA, SEE, and SED, being closely related to the streptococcal toxin SPEC, whereas the other clade depicts close relationships of the staphylococcal toxins SEC and SEB with the streptococcal toxin SPEA.
致热毒素（PT）家族由葡萄球菌肠毒素（SE）、中毒性休克综合征毒素和链球菌致热外毒素（SPE）组成。鉴于PT因其独特的生物学特性而受到大量研究关注，我们对该基因家族进化的理解仍不完整。通过检查先前报道的编码SPEA、SPEC、SEA、SEB、SEC1、SEC2、SEC3、SED和SEE的基因核苷酸序列，估算了PT家族成员的系统发育关系。此外，我们展示并分析了7个先前未报道的sec基因的序列数据。在PT家族中，序列差异以分层方式划分，使得所有16个毒素基因的平均序列差异为1.179，仅限于葡萄球菌的基因平均序列差异为0.443，编码C型SE的10个变体的基因平均序列差异为0.028。本研究结果表明PT家族由两个大的进化枝组成。一个进化枝由葡萄球菌毒素SEA、SEE和SED组成，它们与链球菌毒素SPEC密切相关，而另一个进化枝则显示葡萄球菌毒素SEC和SEB与链球菌毒素SPEA关系密切。
