TABLE 3.

Results of sortase-substrate predictions

Prediction methoda or category	No. of predicted sortase-substrate linkagesb	% of total substrates
Single sortasec	145 (153)	17.1
Single sortase A-single sortase Bd	257 (257)	28.8
Single sortase-single substrate genomic clustere	23 (31)	3.5
Single sortase and single sortase-single substrate genomic cluster	8 (8)	<1.0
Sequence homologyf	163 (411)	46.0
Subfamily-4 sorting signal specificity—LPXTA CWSg	14 (24)	2.7
Subfamily-5 sorting signal specificity—LAXTG CWS	42 (46)	5.2
Subtotal	652	73.0
Genomic cluster with single sortase and multiple substratesh	37 (52)	5.8
Subtotal	689	77.2
Unassigned substrates	203	22.8
Total no. of CWS-containing proteins	892	100

^aGeneral description of method used to link a CWS-containing substrate to a sortase homolog.

^bFirst number is the sum of nonredundant linkages; i.e., linkages predicted exclusively from this method. Number in parentheses is the sum total of linkages made by prediction method, which might include predictions made by more than one method.

^cGenome has only one sortase homolog.

^dGenome has only one sortase A homolog and one sortase B homolog.

^eGenome has one sortase homolog genomically clustered with one CWS-containing protein.

^fPredictions of sortase-substrate linkages are based on sequence homology between a CWS-containing protein in one species and a CWS-containing protein(s) that has been assigned by one of the above three methods.

^gPredictions of sortase-substrate linkages are based on the sorting signals of the CWS-containing proteins. Subfamily-4 sortases are predicted to process CWS-containing proteins with an LPXTA motif, whereas subfamily-5 sortases are predicted to process CWS-containing proteins with a LAXTG motif.

^hGenome has only one sortase homolog that is genomically clustered with two or more CWS-containing proteins (number of predictions excludes SrtB genomic clusters and subfamily-5 substrate in C. diphtheriae).