Frye R A
Pittsburgh V.A. Medical Center (132L), University, Pittsburgh, Pennsylvania 15240, USA.
Biochem Biophys Res Commun. 2000 Jul 5;273(2):793-8. doi: 10.1006/bbrc.2000.3000.
Sirtuins (Sir2-like proteins) are present in prokaryotes and eukaryotes. Here, two new human sirtuins (SIRT6 and SIRT7) are found to be similar to a particular subset of insect, nematode, plant, and protozoan sirtuins. Molecular phylogenetic analysis of 60 sirtuin conserved core domain sequences from a diverse array of organisms (including archaeans, bacteria, yeasts, plants, protozoans, and metazoans) shows that eukaryotic Sir2-like proteins group into four main branches designated here as classes I-IV. Prokaryotic sirtuins include members of classes II and III. A fifth class of sirtuin is present in gram positive bacteria and Thermotoga maritima. Saccharomyces cerevisiae has five class I sirtuins. Caenorhabditis elegans and Drosophila melanogaster have sirtuin genes from classes I, II, and IV. The seven human sirtuin genes include all four classes: SIRT1, SIRT2, and SIRT3 are class I, SIRT4 is class II, SIRT5 is class III, and SIRT6 and SIRT7 are class IV.
沉默调节蛋白（类Sir2蛋白）存在于原核生物和真核生物中。在此，发现两种新的人类沉默调节蛋白（SIRT6和SIRT7）与昆虫、线虫、植物和原生动物沉默调节蛋白的一个特定亚类相似。对来自多种生物（包括古细菌、细菌、酵母、植物、原生动物和后生动物）的60个沉默调节蛋白保守核心结构域序列进行的分子系统发育分析表明，真核生物类Sir2蛋白分为四个主要分支，在此指定为I-IV类。原核生物沉默调节蛋白包括II类和III类成员。第五类沉默调节蛋白存在于革兰氏阳性细菌和嗜热栖热菌中。酿酒酵母有五个I类沉默调节蛋白。秀丽隐杆线虫和黑腹果蝇具有来自I、II和IV类的沉默调节蛋白基因。七个人类沉默调节蛋白基因包括所有四类：SIRT1、SIRT2和SIRT3属于I类，SIRT4属于II类，SIRT5属于III类，SIRT6和SIRT7属于IV类。
