Reaction catalyzed by RBR-type E3 ubiquitin transferase (2.3.2.31)

	[RBR-type E3 ubiquitin transferase]-S-ubiquitinyl-L-cysteine	+		[acceptor protein]-L-lysine	=		[RBR-type E3 ubiquitin transferase]-L-cysteine	+		[acceptor protein]-N6-ubiquitinyl-L-lysine
	[RBR-type E3 ubiquitin transferase]-S-ubiquitinyl-L-cysteine	+		[acceptor protein]-L-lysine	=		[RBR-type E3 ubiquitin transferase]-L-cysteine	+		[acceptor protein]-N6-ubiquitinyl-L-lysine