TABLE 1.

Substrate specificity of P. furiosus FBPase compared to that of M. jannaschii MJ0109^a

Substrate	Relative activity (%)
	P. furiosus FBPase	M. jannaschii MJ0109
Fructose-1,6-bisphosphate	100	100
Inositol-1-phosphate	7.5	61
Glycerol-2-phosphate	1.7	49
Glucose-1-phosphate	2.8	42

^aAssays for P. furiosus FBPase were performed at 85°C as described in the text. The data from assays of MJ0109 performed at 85°C were obtained from Stec et al. (20). An activity of 100% corresponds to 12.2 and 15.2 U/mg for P. furiosus FBPase and MJ0109, respectively. Fructose-1-phosphate, fructose-6-phosphate, glucose-6-phosphate, PEP, 5′-AMP, 5′-ADP, and 5′-ATP could not be used as substrates by the P. furiosus FBPase.