TABLE 1.

Comparison of cPGIs with selected members of the cupin superfamily

Protein	Source	Fold type	Quaternary structure	Metalc	Source or reference
Archaea
PGI	Pyrococcus furiosus, Salmonella enterica serovar Typhimurium, and Ensifer meliloti	Monocupin	α2	Me	2; This work
PGI	Archaeoglobus fulgidus and Methanosarcina mazei	Monocupin	α	Me	This work
PGI	Thermococcus litoralis	Monocupin	α2	Fe and Zn	30
dTDP-6-deoxy-d-xylo-4-hexulose 3,5-epimerase	Methanothermobacter thermoautotrophicus	Monocupin	α2	None	7
Bacteria
AraC	Escherichia coli	Monocupin	α2	None	47
Proline 3-hydroxylase	Streptomyces sp.	Monocupin	α2	Fe	9
dTDP-6-deoxy-d-xylo-4-hexulose 3,5-epimerase	Salmonella enterica serovar Typhimurium	Monocupin	α2	None	1
Oxalate decarboxylase	Bacillus subtilis	Bicupin	α6	Mn	2
Eukarya
Oxalate oxidase	Barley, Hordeum vulgare	Monocupin	α6	Mn	54
Homogentisate dioxygenase	Human	Monocupin	α6	Fea	51
Phosphomannose isomerase	Candida albicans	Bicupin	α	Zn	8
Isopenicillin N-synthase	Emericella nidulans	Monocupin	α	Fe or Mnb	43
Canavalin	Jack bean	Bicupin	α3	None	34
Phaseolin	Phaseolus vulgaris	Bicupin	α3	None	36

^aIron is not associated with the cupin domain.

^bMn was found in the structure.

^c cMe, divalent metal.