A subcomplex of RNA polymerase III subunits involved in transcription termination and reinitiation.
While initiation of transcription by RNA polymerase III (Pol III) has been thoroughly investigated, molecular mechanisms driving transcription termination remain poorly understood. Here we describe how the characterization of the in vitro transcriptional properties of a Pol III variant (Pol IIIdelta), lacking the C11, C37, and C53 subunits, revealed crucial information about the mechanisms of Pol III termination and reinitiation. The specific requirement for the C37-C53 complex in terminator recognition was determined. This complex was demonstrated to slow down elongation by the enzyme, adding to the evidence implicating the elongation rate as a critical determinant of correct terminator recognition. In addition, the presence of the C37-C53 complex required the simultaneous addition of C11 to Pol IIIdelta for the enzyme to reinitiate after the first round of transcription, thus uncovering a role for polymerase subunits in the facilitated recycling process. Interestingly, we demonstrated that the role of C11 in recycling was independent of its role in RNA cleavage. The data presented allowed us to propose a model of Pol III termination and its links to reinitiation.
Landrieux
Emilie
E
CEA/Saclay, Laboratoire de Transcription des Gènes, Service de Biochimie et de Génétique Moléculaire, Gif sur Yvette, France.
Alic
Nazif
N
Ducrot
Cécile
C
Acker
Joël
J
Riva
Michel
M
Carles
Christophe
C
D004252:DNA Mutational Analysis; D008957:Models, Genetic; D009154:Mutation; D021122:Protein Subunits / Q000235:genetics / Q000378:metabolism; D012320:RNA Polymerase III / Q000235:genetics / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000201:enzymology / Q000235:genetics; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism*; D013728:Terminator Regions, Genetic; D014158:Transcription, Genetic
D021122:Protein Subunits; D029701:Saccharomyces cerevisiae Proteins; C508371:RPC11 protein, S cerevisiae; C508372:RPC37 protein, S cerevisiae; C508373:RPC53 protein, S cerevisiae; D012320:RNA Polymerase III