Table 1. Areas under the receiver-operating-characteristic curves.

Interaction Type	Number of known interaction	Size of negative set	AUC
cleavage reaction	153	153	0.82
covalent binding	50	100	0.86
deacetylation reaction	34	100	0.89
dephosphorylation reaction	322	322	0.71
methylation reaction	30	100	0.81
phosphorylation reaction	813	813	0.65
ubiquitination reaction	102	102	0.87
disulfide bond	27	100	0.84
adp ribosylation reaction	54	100	0.97
protein cleavage	43	100	0.97

Areas under the curves (AUC) obtained in a 10-fold cross-validation setting. The AUC is averaged across 20 cross validation repeats.