TABLE 2.

Stopped-flow measurements of biotin transfer rates for cognate and noncognate ligase-BCCP pairs

Pair	HsBCCPa	EcBCCPa	PhBCCPa
	m−1s−1	m−1s−1	m−1s−1
HsBPL	35,000 ± 3000	270 ± 40	NDb
	(0.23 ± 0.02)c
EcBPL	32,000 ± 2000	11,500 ± 700	NDb
	(0.33 ± 0.03)c	(0.21 ± 0.02)c
PhBPL	43,000 ± 5000d	4,200 ± 300d	15,000 ± 600d

^a The errors correspond to the S.D. of three independent stopped-flow experiments.

^b ND, not detectable.

^c BCCP dissociation rate, in s⁻¹.

^d Measurements with PhBPL were carried out at 40 °C, in 10 mm Tris, pH 7.5, 500 mm KCl, 2.5 mm MgCl₂. All other experiments were performed at 20 °C, in 10 mm Tris, pH 7.5, 200 mm KCl, 2.5 mm MgCl₂.