Loss of the Rpb4/Rpb7 subcomplex in a mutant form of the Rpb6 subunit shared by RNA polymerases I, II, and III.

ABSTRACT: We have identified a conditional mutation in the shared Rpb6 subunit, assembled in RNA polymerases I, II, and III, that illuminated a new role that is independent of its assembly function. RNA polymerase II and III activities were significantly reduced in mutant cells before and after the shift to nonpermissive temperature. In contrast, RNA polymerase I was marginally affected. Although the Rpb6 mutant strain contained two mutations (P75S and Q100R), the majority of growth and transcription defects originated from substitution of an amino acid nearly identical in all eukaryotic counterparts as well as bacterial omega subunits (Q100R). Purification of mutant RNA polymerase II revealed that two subunits, Rpb4 and Rpb7, are selectively lost in mutant cells. Rpb4 and Rpb7 are present at substo

SUBMITTER: Tan Q 

PROVIDER: S-EPMC153193 | biostudies-literature | 2003 May

REPOSITORIES: biostudies-literature