Table 1.
Effect of cbiZ and bluB mutations on cobamide accumulation. a
| Genotype | Corrinoid added b | Percent total cobamide (in 2-min fractions) | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| 20 | 22 | 24 | 26 | 28 | 30 | 32 | 34 | 36 | 38 | ||
| ΔcobB | (CN)2Cbi | 1 | 2 | 14 | 60 | 23 | |||||
| ΔcobB | CNpseudoCbl | 2 | 25 | 63 | 10 | ||||||
| ΔcobB ΔcbiZ | CNpseudoCbl | 100 | |||||||||
| ΔcobB | (CN)2Cbi | 84 | 16 | ||||||||
| bluB∷aadA | |||||||||||
| Elution profiles of known cobamide standards c | |||||||||||
| Cobamide | 20 | 22 | 24 | 26 | 28 | 30 | 32 | 34 | 36 | 38 | |
| CNCbl | 3 | 30 | 61 | 5 | 1 | ||||||
| CNpseudoCbl | 95 | 5 | |||||||||
a
Cobamides accumulated by R. sphaeroides strains grown aerobically in mSistrom’s medium supplemented with succinate (30 mM) and the indicated corrinoids were separated by RP-HPLC; 2 min fractions were collected starting at the indicated times. The cobamide content in each fraction was determined by bioassay and normalized to the percentage of the total cobamide detected in the sample.
b
Corrinoids were added at 50 nM.
c
Authentic CNCbl and CNpseudoCbl standards were separated by RP-HPLC. The cobamide content in fractions was determined by bioassay and normalized to the percentage of the total corrinoid injected in the known sample.