Glycan structures present in the different glycoforms of RNase B. M, mannose; G, N-acetylglucosamine; Asn, asparagine residue in the polypeptide. Mannose residues are linked via α(1→2), α(1→3), α(1→6), and β(1→4) linkages, which are indicated by the numbers 2, 3, 6, and 4, respectively.