May be involved in the early steps of the plant defense signaling pathway. 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. Up-regulated by chitin. The RING-type zinc finger domain mediates binding to an E2 ubiquitin-conjugating enzyme. Belongs to the RING-type zinc finger family. ATL subfamily. The predicted gene At4g15970 has been split into 2 genes: At4g15970 and At4g15975. The predicted gene At4g15970 has been split into 2 genes: At4g15970 and At4g15975.