Fig. 1: Summary of mucinases/O-glycoproteases cleavage motif.

a The O-glycosylation biosynthetic pathway. The GalNAc, Gal, GlcNAc, and Sia are represented as a yellow square, a yellow circle, a blue square, and a magenta diamond, respectively, and according to the symbol nomenclature for glycans (SNFG) described for these monosaccharides60. b Cleavage motifs for the mucinases and O-glycoproteases described in the previous literature. The accepted subsite nomenclature for the amino acids and the sugar moieties of the glycoprotein substrates are indicated for StcE, BT4244, AM0627, and ZmpC as representative examples of these enzymes, and the red arrow indicates the cleaved point. Parentheses indicate less favored O-glycan structures and n.d. indicates that the glycan specificity is not determined.