Probable component of the HRD1 ubiquitin ligase complex that mediates the rapid degradation of misfolded endoplasmic reticulum (ER) proteins, a process called ER-associated degradation (ERAD). Targets the misfolded LRR receptor kinase BRI1. Functions redundantly with HRD3B. S-ubiquitinyl-[E2 ubiquitin-conjugating enzyme]-L-cysteine + [acceptor protein]-L-lysine = [E2 ubiquitin-conjugating enzyme]-L-cysteine + N(6)-ubiquitinyl-[acceptor protein]-L-lysine. Protein modification; protein ubiquitination. Belongs to the HRD1 family.