TABLE 1.

IC₅₀ values derived from scans of gels as exemplified in Fig. 2

Antibiotic	IC50 (μM) for enzymea:
	Supercoiling		Decatenation		Relaxation
	Gyrase		Topoisomerase IV		Gyrase		Topoisomerase IV
	E. coli	S. aureus	E. coli	S. aureus	E. coli	S. aureus	E. coli	S. aureus
Ciprofloxacin	0.2	27	2.1	6.1	0.2	7.7	3.5	0.2
Moxifloxacin	1.1	17	2.0	3.8	0.8	3.3	2.8	1.0
NXL101	11	1.0	2.2	18	23	0.4	0.2	0.3

^aThe IC₅₀ is the concentration of compound required to inhibit 50% of the reaction. Each value is the average of at least two assays.