TABLE 1.

The β-galactosidases of known structure

Protein	GH family	PDB code	Reference
S. solfataricus β-gal	GH-1	1UWQ	Ref. 27
E. coli β-gal	GH-2	1BGM	Ref. 22
Arthrobacter sp. C2-2 C221 β-gal	GH-2	1YQ2	Ref. 23
K. lactis β-gal	GH-2	3OBA	Ref. 24
Penicillium sp. β-gal	GH-35	1TG7	Ref. 28
B. thetaiotaomicron β-gal	GH-35	3D3A	Unpublisheda
T. reesei β-gal	GH-35	3OG2	Ref. 29
H. sapiens β-gal	GH-35	3THC	Ref. 30
T. thermophilus A4 β-gal	GH-42	1KWG	Ref. 25
B. circulans sp. alkalophilus β-gal	GH-42	3TTS	Ref. 26

^a K. Palani, D. Kumaran, S. K. Burley, and S. Swaminathan, unpublished results.