A class of enzymes that form a thioester bond to UBIQUITIN with the assistance of UBIQUITIN-ACTIVATING ENZYMES. They transfer ubiquitin to the LYSINE of a substrate protein with the assistance of UBIQUITIN-PROTEIN LIGASES. (mesh:D044763)
| Synonym | Reference | Specificity |
| E2 enzyme | Exact | |
| E2 ubiquitin-conjugating enzyme | Exact | |
| ubiquitin-conjugating enzymes | Exact | |
| UBE2 | Exact | |
| E2 conjugating enzyme | Exact | |
| ubiquitin conjugating enzyme | Exact |
| Identifier | Name | Relation |
| HGNC:12490 | UBE2L6 | isa |
| HGNC:12474 | UBE2D1 | isa |
| HGNC:12495 | UBE2V2 | isa |
| HGNC:12473 | UBE2B | isa |
| HGNC:1734 | CDC34 | isa |
| HGNC:12485 | UBE2I | isa |
| HGNC:12476 | UBE2D3 | isa |
| HGNC:12484 | UBE2H | isa |
| HGNC:15698 | UBE2Q1 | isa |
| HGNC:12479 | UBE2E3 | isa |
| HGNC:25616 | UBE2W | isa |
| HGNC:12488 | UBE2L3 | isa |
| HGNC:17598 | UBE2J1 | isa |
| HGNC:12478 | UBE2E2 | isa |
| HGNC:12477 | UBE2E1 | isa |
| HGNC:12494 | UBE2V1 | isa |
| HGNC:12482 | UBE2G1 | isa |
| HGNC:19268 | UBE2J2 | isa |
| HGNC:12483 | UBE2G2 | isa |
| HGNC:12472 | UBE2A | isa |
| HGNC:19907 | UBE2R2 | isa |
| HGNC:17895 | UBE2S | isa |
| HGNC:12491 | UBE2M | isa |
| HGNC:12492 | UBE2N | isa |
| HGNC:21647 | UBE2D4 | isa |
| HGNC:12480 | UBE2F | isa |
| HGNC:15937 | UBE2C | isa |
| HGNC:31710 | UBE2NL | isa |
| HGNC:12475 | UBE2D2 | isa |