TABLE 1.
Kinetic parameters for RifR hydrolysis of acyl substrates
|
Substrate
|
kcat/Km
|
Ratio
|
||||
|---|---|---|---|---|---|---|
| Wild type RifR | S94A RifR | Wild type/S94A | ACP/CoA | |||
| m–1 s–1 | ||||||
| CoA substrates | ||||||
| Decanoyl-CoA | CH3-(CH2)8-CO-S-CoA | 160 ± 18 | <0.16 | >1000 | ||
| Octanoyl-CoA | CH3-(CH2)6-CO-S-CoA | 31 ± 2.5 | <0.16 | >190 | ||
| Propionyl-CoA | CH3-CH2-CO-S-CoA | 25 ± 0.5 | 0.96 ± 0.37 | 26 | ||
| Butyryl-CoA | CH3-(CH2)2-CO-S-CoA | 13 ± 3.2 | <0.04 | >340 | ||
| Acetyl-CoA | CH3-CO-S-CoA | 11 ± 0.2 | <0.03 | >320 | ||
| Isobutyryl-CoA | (CH3)2-CH-CO-S-CoA | 9.6 ± 0.08 | 4.5 ± 0.08 | 2.1 | ||
| Hexanoyl-CoA | CH3-(CH2)4-CO-S-CoA | 5.9 ± 0.33 | <0.04 | >140 | ||
| Methylmalonyl-CoA | CO2-(CH3)CH2-CO-S-CoA | 1.8 ± 0.17 | <0.03 | >72 | ||
| Malonyl-CoA | CO2-CH2-CO-S-CoA | 1.5 ± 0.08 | <0.07 | >21 | ||
| ACP substrates | ||||||
| Propionyl-RifM1 | CH3-CH2-CO-S-ACP | 210 ± 20 | 8.4 | |||
| Acetyl-RifM1 | CH3-CO-S-ACP | 150 ± 38 | 14 | |||
| Methylmalonyl-RifM1 | CO2-(CH3)CH2-CO-S-ACP | 54 ± 6.3 | 30 | |||