DTS2 comprises a region of chromosome XV that embraces the complete AZF1, YOR114w, TRS33, and RPO31 genes, plus a 3′ fragment of the CEX1 gene (Figure 3, bottom panel). When 2-µ vectors containing the individual AZF1, YOR114w, TRS33, and RPO31 open reading frames and ∼200–400 bp of 5′ and 3′ flanking genomic DNA were transformed into tgs1∆ cells, only RPO31 revived growth at 18° compared to the vector control (Figure 3, bottom panel). Rpo31 encodes the 1460-amino acid largest subunit of nuclear RNA polymerase III. Side-by-side comparison of the growth of tgs1∆ cells bearing 2-µ RPO26 or RPO31 plasmids revealed that RPO26 was a better suppressor of the cold-sensitive defect, as gauged by colony size (Figure 3, bottom panel).