ID 2.4.1.212 DE Hyaluronan synthase. AN HAS. CA (1) UDP-alpha-N-acetyl-D-glucosamine + beta-D-glucuronosyl-(1->3)-N- CA acetyl-beta-D-glucosaminyl-(1->4)-(nascent hyaluronan) = UDP + N-acetyl- CA beta-D-glucosaminyl-(1->4)-beta-D-glucuronosyl-(1->3)-N-acetyl-beta-D- CA glucosaminyl-(1->4)-(nascent hyaluronan). CA (2) UDP-alpha-D-glucuronate + N-acetyl-beta-D-glucosaminyl-(1->4)-beta-D- CA glucuronosyl-(1->3)-(nascent hyaluronan) = UDP + beta-D-glucuronosyl- CA (1->3)-N-acetyl-beta-D-glucosaminyl-(1->4)-beta-D-glucuronosyl- CA (1->3)-(nascent hyaluronan). CF Magnesium. CC -!- Adds GlcNAc to nascent hyaluronan when the non-reducing end is GlcA, CC but it adds GlcA when the non-reducing end is GlcNAc. CC -!- Highly specific for UDP-GlcNAc and UDP-GlcA; no copolymerization is CC observed if either is replaced by UDP-Glc, UDP-Gal, UDP-GalNAc or CC UDP-GalA. DR Q92839, HAS1_HUMAN ; Q61647, HAS1_MOUSE ; P13563, HAS1_XENLA ; DR O97711, HAS2_BOVIN ; O57424, HAS2_CHICK ; Q92819, HAS2_HUMAN ; DR P70312, HAS2_MOUSE ; O35776, HAS2_RAT ; O57427, HAS2_XENLA ; DR O57425, HAS3_CHICK ; O00219, HAS3_HUMAN ; O08650, HAS3_MOUSE ; DR O57426, HAS3_XENLA ; P0C0H1, HASA_STRP1 ; Q8K5G6, HASA_STRP3 ; DR Q5X9A9, HASA_STRP6 ; Q8NKX1, HASA_STRP8 ; P0C0H0, HASA_STRPY ; DR Q7BLV3, HAS_PASMU ; //