The ubiquitin (Ub) pathway involves three sequential enzymatic steps that facilitate the conjugation of Ub and Ub-like molecules to specific protein substrates. The first step requires the ATP-dependent activation of the Ub SLCterminus and the assembly of multi-Ub chains by the Ub-activating enzyme known as the E1 component. The Ub chain is then conjugated to the Ub-conjugating enzyme (E2) to generate an intermediate Ub-E2 complex. The Ub-ligase (E3) then catalyzes the transfer of Ub from E2 to the appropriate protein substrate. UBE2A (Ubiquitin-conjugating enzyme E2 A) and UBE2B (Ubiquitin-conjugating enzyme E2 B) are both Ub-conjugating enzymes that are essential to postreplication repair of USLVdamaged DNA. UBE2A and UBE2B are both nuclear and cell membrane proteins that have been found to interact with Rad18.
Function:
Accepts ubiquitin from the E1 complex and catalyzes its covalent attachment to other proteins. In association with the E3 enzyme BRE1 (RNF20 and/or RNF40), it plays a role in transcription regulation by catalyzing the monoubiquitination of histone H2B at 'Lys-120' to form H2BK120ub1. H2BK120ub1 gives a specific tag for epigenetic transcriptional activation, elongation by RNA polymerase II, telomeric silencing, and is also a prerequisite for H3K4me and H3K79me formation. In vitro catalyzes 'Lys-11', as well as 'Lys-48'-linked polyubiquitination. Required for postreplication repair of USLVdamaged DNA.
Subunit:
Interacts with RAD18 and WAC.
DISEASE:
Defects in UBE2A are the cause of mental retardation syndromic X-linked Nascimento-type (MRXSN) [MIM:300860]. Mental retardation is characterized by significantly below average general intellectual functioning associated with impairments in adaptative behavior and manifested during the developmental period. MRXSN features include dysmorphic facies, hirsutism, skin and nails abnormalities, obesity, speech anomalies and seizures.
Similarity:
Belongs to the ubiquitin-conjugating enzyme family.
SWISS:
P49459
Gene ID:
7319
Database links:
Entrez Gene: 395672 Chicken
Entrez Gene: 282107 Cow
Entrez Gene: 7319 Human
Entrez Gene: 22209 Mouse
Entrez Gene: 298317 Rat
Entrez Gene: 398788 Xenopus laevis
Entrez Gene: 797853 Zebrafish
Omim: 31236 Human
SwissProt: P49459 Human
SwissProt: P63146 Human
SwissProt: Q9Z255 Mouse
Unigene: 379466 Human
Unigene: 395649 Mouse
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