cDNA cloning, characterization, and chromosome mapping of UBE2E2 encoding a human ubiquitin-conjugating E2 enzyme

A cDNA encoding a human ubiquitin-conjugating enzyme (E2) with N-terminal extension (UBE2E2/UbcH8) was isolated. Amino acid sequence within the UBC domain of UBE2E2 shares over 90% identity with human UbcH6, mouse UbcM2, and Drosophila UbcD2, whereas the N-terminal region shows little amino acid sequence similarity with known proteins. The UBE2E2 gene is transcribed in various tissues as a 1.9-kb transcript. The UBE2E2 protein formed a thioester bond with ubiquitin in an E1-dependent manner, indicating that the gene product is a functional E2 enzyme. The UBE2E2 gene was assigned to human chromosome 3p24.2 by fluorescence in situ hybridization.