Figure 1

(A) A summary of amino acid substitutions in HTLV-1 tax point mutants whose expression did not cause growth arrest in S. cerevisiae. The complete amino acid sequence of HTLV-1 Tax is shown with the amino acid alteration in each point mutant indicated above. (B) Expression of 5 representative HTLV- tax point mutants in S. cerevisiae. W303-1a cells were transformed with the Gal10-Tax (WT-Tax) or its equivalent carrying each of five mutant tax alleles and plated on agar plates containing 2% raffinose or 2% raffinose plus 2% galactose. The amino acid alterations in tax mutants are as indicated.