5.4.99.30 glycoprotein autoglycosylation occurs at a specific arginyl residue in recombinant UDP-arabinopyranose mutase that is essential for mutase activity 5.4.99.30 glycoprotein rUAM1 is autoglycosylated when each protein reacts separately with UDP-Glc. Reversibly glycosylated in the presence of UDP-Glc 5.4.99.30 glycoprotein rUAM3 is autoglycosylated when each protein reacts separately with UDP-Glc. Reversibly glycosylated in the presence of UDP-Glc 5.4.99.30 glycoprotein the enzyme is a reversibly glycosylated protein