INTERACTION BETWEEN A COMPLEX OF RNA POLYMERASE-III SUBUNITS AND THE 70-KDA COMPONENT OF TRANSCRIPTION FACTOR-IIIB

A system that detects the formation of complexes between different pro teins by linking them to separate domains of the GALA transcription ac tivator protein has been used to study protein-protein interactions be tween four essential and unique subunits of yeast RNA polymerase III ( C82, C53, C34 and C31), the 70-kDa component of the initiation transcr iption factor IIIB (TFIIIB70) and the TATA-binding protein. We found t hat C82, C34, and C31 are able to combine with each other in vivo and that C34 interacts with TFIIIB70. These results suggest that C34 and T FIIIB70 are specificity determinants of the RNA polymerase III-TFIIIB interaction.