Table 1.

N-terminal nucleophile hydrolase families

SCOP family	Representative structure	Nucleophile	MEROPS family
Penicillin V acylase	3pvaA	Cys	C45
Class II glutamine amidotransferases	1ecfB	Cys	C44
Penicillin G acylase	1ajqB	Ser	S45
Proteasome catalytic subunits	1pmaP	Thr	T1
(Glycosyl)asparaginase	1apyB	Thr	T2