FIG. 1.

Functional analysis of truncated mutants of Rpb6. Expression plasmids for N- and C-terminal deletion mutants of rpb6 were constructed using vector pAI-ARS and transformed into S. pombe SpRpb6::ura4 containing pREP81-Rpb6 (Table 2). In the absence of thiamine, the intact Rpb6 is expressed from pREP81-Rpb6 (agar plate, upper panel); its expression is repressed by the addition of thiamine (agar plate, lower panel). The functional integrity of truncated Rpb6 mutants was tested in the absence of intact Rpb6.