TABLE 2.
Growth phenotypes caused by point mutations in the Walker motifs of Rvb2pa
| Motif | Mutation | Phenotype at:
|
||
|---|---|---|---|---|
| 16°C | 30°C | 37°C | ||
| Walker A | G75A | − | − | − |
| G80A | + | + | − | |
| K81R | − | +++ | − | |
| K81A | + | + | − | |
| T82S | + | + | + | |
| Walker B | I295V | +++ | +++ | +++ |
| E297D | ++ | +++ | ++ | |
| V298G | +++ | +++ | +++ | |
| D296N | − | − | − | |
a
Mutations were made in the A and B elements by site-directed mutagenesis. The mutant alleles were inserted individually into a TRP/CEN vector (Table 1) and then introduced into a strain with an inactive rvb2 chromosomal gene (YTK86, with an rvb2::HIS3 allele) and a plasmid-borne copy of wild-type RVB2 (PTK123). The latter plasmid was evicted by curing on 5-FOA. Growth phenotypes were assessed on YPD at 3 days (30°C) or 7 days (16 and 37°C). +++, wild-type growth rate; ++, slow growth; +, very slow growth; −, lethal.