Function
Ubiquitin activating enzyme (Uba) or E1 enzyme catalyzes the first step in the ubiquitination of a protein tagged to be degraded by the proteasome. Ubiquitin activating enzyme (E1) and ATP produce a C-terminal acyl adenylated ubiquitin molecule which binds to ubiquitin conjugating enzyme (E2) (Ubc) cysteine[1]. The Ubc then binds to ubiquitin ligase (E3) via a conserved binding region. E3 catalyzes the transfer of ubiquitin from the Ubc-ubiquitin complex to a lysine residue of the target protein.
- Uba1 see Uba1.
- Uba3 is the catalytic subunit of NEDD8 activating enzyme and APPB1 is its regulatory subunit. Similar to ubiquitin and SUMO, NEDD8 binds to proteins after processing of its C-terminal.
- Uba6 regulates the interferon-gamma production of T-cells by modulating NF-κB activation pathway[2].
For ubiquitin-like modifier-activating enzyme Atg7 see Autophagy-related protein
(PDB entry 1y8x). .
