Table 2.
Characteristics of BirA mutants that are defective in repression or enzymatic function
| Allele | Biotin requirement (μM) | Repression (1 mM biotin) | Mutation position | Amino acid substitution |
|---|---|---|---|---|
| birA (wt) | <4.1 (43°C) | + | — | — |
| birA879 | 1.6–41 (29°C) | − | 83 | Val → Gly |
| birA815 | 41–4,100 (43°C) | + | 107 | Cys → Gly |
| birA1 | 41–4,100 (43°C) | + | 115 | Gly → Ser |
| birA91 | 4.1–41 (43°C) | − | 118 | Arg → Gly |
| birA352 | <4.1 (43°C) | − | 119 | Arg → Trp |
| birA71 | 1.6–41 (29°C) | − | 142 | Gly → Cys |
| birA881 | <4.1 (43°C) | − | 146 | Ala deleted |
| birA215 | 41–4,100 (43°C) | + | 189 | Val → Gly |
| birA301 | <4.1 (43°C) | − | 197 | Asp → Tyr |
| birA104 | 41–4,100 (29°C) | + | 207 | Ile → Ser |
| birA85 | 41–4,100 (29°C) | − | 235 | Arg → Gly |