泛素
       泛素是一个含有76个氨基酸的存在于细胞核和细胞质中的高度保守的蛋白质。泛素只存在于真核细胞中，在泛素蛋白酶体通路（UPP）中，通过酶的作用能够与底物蛋白供价结合。泛素蛋白的氨基酸序列如下：MQIFVKTLTGKTITLEVEPSDTIENVKAKIQDKEGIPPDQQRLIFAGKQLEDGRTLSDYNIQKESTLHLVLRLRGG

Ubiquitin
        Ubiquitin is a 76 amino acid, highly conserved nuclear and cytoplasmic protein. It is found exclusively in eukaryotes, becomes covalently attached to substrate proteins by enzymes in the Ubiquitin-Proteosome Pathway (UPP) and has a major role in targeting cellular proteins for the ATP-dependent degradation by the 26S proteosome. Ubiquitination also affects proteosome-independent events such as protein localization, activity and function. 
Sequence in amino acid abbreviations is MQIFVKTLTGKTITLEVEPSDTIENVKAKIQDKEGIPPDQQRLIFAGKQLEDGRTLSDYNIQKESTLHLVLRLRGG