Table 1.
Complementation and transport by IRT1 point mutants
| Substitution | Complements
defect in
|
|||
|---|---|---|---|---|
| Fe transport | Mn transport | Zn transport | Sensitive to Cd | |
| None (wild type) | + | + | + | + |
| H96A | − | − | − | − |
| D100A | − | − | + | + |
| E103A | + | + | − | + |
| D100A E103A | − | − | + | + |
| C109A | + | + | + | + |
| D136A | − | − | + | − |
| H197A | − | − | − | − |
| H197E | − | − | − | − |
| S198A | − | − | − | − |
| H224A | − | − | − | − |
| E228A | − | − | − | − |
| Y295A | + | +* | + | + |
| D300A | + | +* | + | + |
| E305A | + | +* | + | + |
All mutant IRT1 alleles were expressed in four different yeast strains (fet3 fet4, smf1, zrt1 zrt2, and wild type) to determine their ability to complement various yeast transport mutants and to confer cadmium sensitivity.
*
Colonies slightly smaller than wild type, indicating less manganese transport ability.