<p>Suppression of the <i>orc4-R267A</i> lethal phenotype by different general transcription factor alleles.</p>

<p>Ten-fold serial dilutions of <i>orc4-R267A</i> plasmid-shuffle strains without and with additional point mutations in the indicated genes involved in RNA Pol II transcription. Strains were incubated for 4 days at 25 °C. <i>orc4-</i> and <i>toa2-sofa</i> alleles are included as references. For TBP, we designed <i>spt15</i> alleles according to the crystal structure (A86D, R107A) and tested previously-reported alleles that disrupt TFIIA (K133R, Y139A) or TFIIB (E188A) binding [<a href="plosone.org/article/info:doi/10.1371/journal.pone.0349465#pone.0349465.ref049" target="_blank">49</a>,<a href="plosone.org/article/info:doi/10.1371/journal.pone.0349465#pone.0349465.ref050" target="_blank">50</a>,<a href="plosone.org/article/info:doi/10.1371/journal.pone.0349465#pone.0349465.ref068" target="_blank">68</a>,<a href="plosone.org/article/info:doi/10.1371/journal.pone.0349465#pone.0349465.ref069" target="_blank">69</a>].

For the rest of the general transcription factors, we tested two <i>sua7</i> (TFIIB) alleles (K201I and F289S) [<a href="plosone.org/article/info:doi/10.1371/journal.pone.0349465#pone.0349465.ref070" target="_blank">70</a>], a deletion of the non-essential <i>DST1</i> gene (TFIIS) [<a href="plosone.org/article/info:doi/10.1371/journal.pone.0349465#pone.0349465.ref071" target="_blank">71</a>,<a href="plosone.org/article/info:doi/10.1371/journal.pone.0349465#pone.0349465.ref072" target="_blank">72</a>], two <i>ssl2</i> (a subunit of TFIIH) alleles (H508R and V552I/E556K) [<a href="plosone.org/article/info:doi/10.1371/journal.pone.0349465#pone.0349465.ref073" target="_blank">73</a>,<a href="plosone.org/article/info:doi/10.1371/journal.pone.0349465#pone.0349465.ref074" target="_blank">74</a>], and two mutations in <i>rpo21</i> (M818I and G1437D) [<a href="plosone.org/article/info:doi/10.1371/journal.pone.0349465#pone.0349465.ref075" target="_blank">75</a>].</p>