Reaction catalyzed by RING-type E3 ubiquitin transferase (2.3.2.27)

	S-ubiquitinyl-[E2 ubiquitin-conjugating enzyme]-L-cysteine	+		[Ring1b]-L-lysine	=		[E2 ubiquitin-conjugating enzyme]-L-cysteine	+		N6-ubiquitinyl-[Ring1b]-L-lysine
	S-ubiquitinyl-[E2 ubiquitin-conjugating enzyme]-L-cysteine	+		[Ring1b]-L-lysine	=		[E2 ubiquitin-conjugating enzyme]-L-cysteine	+		N6-ubiquitinyl-[Ring1b]-L-lysine