Reaction catalyzed by mannuronate-specific alginate lyase (4.2.2.3)

		=			+
	tetra-beta1,4-D-mannuronic acid	=		4-deoxy-alpha-L-erythro-hex-4-enuronosyl-beta-1,4-D-mannuronoyl-beta-1,4-D-mannuranote	+		D-mannuronate