ST3 beta-galactoside alpha-2,3-sialyltransferase 4 MVSKSRWKLL AMLALVLVVM VWYSISREDR YIELFYFPIP EKKEPCLQGE AESKASKLFG NYSRDQPIFL RLEDYFWVKT PSAYELPYGT KGSEDLLLRV LAITSSSIPK N