Reaction catalyzed by polypeptide N-acetylgalactosaminyltransferase (2.4.1.41)

		+		fibronectin	=			+		N-acetyl-D-galactosaminyl-fibronectin
	UDP-N-acetyl-D-galactosamine	+		fibronectin	=		UDP	+		N-acetyl-D-galactosaminyl-fibronectin