TABLE 1.
Substrate specificity of the cellobiose binding protein CbtA and growth of P. furiosus on various sugars
| Competing substrate | Residual [3H]cellobiose bindinga (% [mean ± SEM] of control) | Growthb |
|---|---|---|
| Cellobiose | 11 ± 1 | + |
| Cellotriose | 12 ± 2 | + |
| Cellotetraose | 9 ± 1 | + |
| Cellopentaose | 10 ± 0.7 | + |
| Laminaribiose | 17 ± 3 | + |
| Laminaritriose | 12 ± 1 | ND |
| Sophorose | 33 ± 15 | + |
| Gentiobiose | 109 ± 26 | − |
| β,β-Trehalose | 89 ± 16 | − |
| Maltose | 100 ± 17 | + |
| Glucose | 85 ± 8 | − |
a
Binding of 200 nM [3H]cellobiose to purified CbtA was measured in the absence and presence of 2 μM concentrations of the indicated nonlabeled sugar substrates. Experiments were performed in triplicate with the indicated standard error of the mean.
b
Growth in the presence of 0.1% (wt/vol) of the indicated sugar as the sole carbon and energy source. +, growth; −, no growth; ND, not determined. Growth experiments were performed in duplicate.