TABLE 1.

Purification of RI from C. laevoribosii RI-39 and recombinant CLRI expressed in E. coli^a

Enzyme	Purification step	Protein (mg)	Activity (U)	Sp act (U/mg)	Yield (%)	Purification (fold)
Native CLRI	Cell extract	880	52.7	0.06	100	1
	DEAE-Sephacel	22	23.2	1.05	44	18
	RESOURCE PHE	4.2	8.4	2.0	16	33
Recombinant CLRI	Cell extract	200	120	0.6	100	1
	DEAE-Sephacel	22	63.7	2.9	46	5
	Superdex 75	12	50.2	4.2	41	7

^aEnzyme activity was measured at 70°C using l-ribose as the substrate (see Materials and Methods).