Figure 1.

Sam37 is a multicopy suppressor for sam35 alleles. (A) Δsam35 cells expressing wild-type SAM35 or sam35-424 from a plasmid and transformed with the indicated multicopy plasmids, were grown to mid-logarithmic phase. Five-fold serial dilutions were spotted onto synthetic complete medium (with glucose as a carbon source) lacking tryptophan and leucine, and plates were incubated at the indicated temperatures for 3 d. (B) Overexpression of Sam37 suppresses sam35-409 phenotype at restrictive temperature. Same as in A, except Δsam35 cells were transformed with plasmids encoding sam35-409 instead. (C) Sam37 and Sam35 are not functionally redundant. NCY0601 (heterozygous diploid SAM35/Δsam35) cells were transformed with a multicopy vector alone (YEplac195) or with the same vector containing SAM35 (YEpSam35) or SAM37 (YEpSam37). Transformed cells were sporulated and tetrads dissected on rich medium containing glucose. Results for four dissected asci are shown.