【背景资料】:UBE2S 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.K11-linked ubiquitin molecules are abundant in vivo and, as for K48-linked chains, are thought to be efficient signals for proteasomal degradation. The human anaphase-promoting complex (APC/C) has been shown to assemble K11 linkages on its substrates, utilizing the E2 conjugating enzymes Ube2C (UbcH10) and Ube2S in the process. This suggests a key role for K11-linked ubiquitin chains and Ube2S in cell cycle progression. Overexpression of Ube2S has been linked to tumour cell proliferation and metastasis through its effects on the pVHL-HIF pathway.Recombinant protein expressed with N-terminal GST-tag. Protein has utility in ubiquitination reactions, polyubiquitin chain synthesis and identification of substrate specific E2-E3 pairs.