【背景资料】:UbcH6, also known as UBE2E1, is a member of the ubiquitin E2 conjugating enzyme family, essential components of the ubiquitin cascade.The selectivity of the ubiquitin cascade for a particular substrate protein relies on the interaction between the E2 conjugating enzyme (of which a cell contains relatively few) and an ubiquitin E3 ligase, of which over 600 have been identified to date. The specific E2-E3 pair required for ubiquitination of a particular substrate protein in vivo may also control the type of ubiquitin modification (mono-, multi-, poly-ubiquitin), the exact substrate lysine residue(s) to be modified and, in the case of polyubiquitination, the chain length and lysine linkage type.UbcH6 is a tumour suppressor candidate which also modulates the transcriptional repression activity of Ataxin-1, the gene product of Spinocerebellar ataxia type 1 (SCA1). SCA1 is an autosomal-dominant neurodegenerative disorder characterized by ataxia and progressive motor deterioration, which is caused by expansion of the polyglutamine tract in Ataxin-1. UbcH6 has also be shown to act as an E2 conjugating enzyme for ISG15.Recombinant human UbcH6 protein expressed with a N-terminal His-tag. Protein has utility in ubiquitination reactions, polyubiquitin chain synthesis, identification of substrate specific E2-E3 pairs and determination of E2 polyubiquitin linkage specificity.