. 2015 Oct 28;29(1):29–57. doi: 10.1128/CMR.00019-15

TABLE 5.

Molecular characteristics of class A β-lactamases according to subclass

Subclass	Cluster	Typical enzyme(s)	Residue(s) at amino acid position(s):
Subclass	Cluster	Typical enzyme(s)	70	73	77	130–132	136	166	179	233	234–236	237–238	245–246
A1a	Gram positive	PC1, BlaU, BlaL	S	K		SDN^a	N	E	D	D	KT^bG	AG	ND
	MYC1	BlaC	S	K		SDG	N	E	D	D	KTG	T^bG	ND
A1b	LSBL1/4	TEM-1, SHV-1	S	K	C^c	SDN	N	E	D	D	KT^bG	AG	G^dI^e
	LSBL2	PSE-1, CARB-3	S	K	C^c	SDN	N	E	D	D	RSG	AG	G^dI^e
	LSBL3	BlaP, RTG-2	S	K	C^c	SDN	N	E	D	D	RTG	AG	G^dI^e
A1c	ESBL1/2	CTX-M, BES-1	S	K		SDN	N	E	D	D	KT^bG	T^fG	ND
	CARBA	NMCA, KPC-2	S	K		SDN	N	E	D	D	KTG	TC^gG	ND
	ESBL3	GES-1, BEL-1	S	K		SDN	N	E	D	E^h	KTG	T^bC	ND
	BURK	BPS-1, PenI	S	K		SDN	N	E	D	D	KTG	TG	ND
A2a		PER-1, VEB-1	S	K		SDN	D	E	N	Hⁱ	KTG	T^bS^j	ND

Ser for some Bacillus species.

Or an analogue (Ser).

Presence of a disulfide bridge between Cys77 and Cys123.

Or an analogue (Ala) or Ser.

Or an analogue (Val).

Ala or Gly for some Enterobacteriaceae (K. oxytoca and C. amalonaticus).

Presence of a disulfide bond between Cys69 and Cys238.

Or an analogue (Asp).

ⁱ

Or an analogue (Arg).

Or Glu for CblA and CfxA types and some CepA types.