Table 2.

General characteristics of bacterial O-linking OTases.

OTase	Protein size (amino acids)	Sugar monomers transferred	Glycan reducing-end tolerance	Native substrate protein(s)	Glycosylation site	References
TfpM	420–440	No known limits	Glc, Gal, 2-N-acetyl sugars	Type IV pilin-like proteins	C-terminal serine or threonine	This work
TfpO (PilO)	440–470	Roughly 3–6	2-N-acetyl sugars, possibly more	PilA	C-terminal serine or threonine	Castric et al. (2001), Comer Jason et al. (2002), DiGiandomenico et al. (2002), Nguyen et al. (2012), Harding et al. (2015)
PglL	550–600	No known limits	Gal, 2-N-acetyl sugars	Many, including PilE	Protein-internal sequon	Faridmoayer et al. (2007), Faridmoayer et al. (2008), Vik et al. (2009), Hayes et al. (2021)
PglS	520–550	No known limits	Glc, Gal, 2-N-acetyl sugars	ComP	Protein-internal sequon	Harding et al. (2015), Harding et al. (2019)