A protein-protein interaction map of yeast RNA polymerase III.
The structure of the yeast RNA polymerase (pol) III was investigated by exhaustive two-hybrid screening using a library of random genomic fragments fused to the Gal4 activation domain. This procedure allowed us to identify contacts between individual polypeptides, localize the contact domains, and deduce a protein-protein interaction map of the multisubunit enzyme. In all but one case, pol III subunits were able to interact in vivo with one or sometimes two partner subunits of the enzyme or with subunits of TFIIIC. Four subunits that are common to pol I, II, and III (ABC27, ABC14.5, ABC10alpha, and ABC10beta), two that are common to pol I and III (AC40 and AC19), and one pol III-specific subunit (C11) can associate with defined regions of the two large subunits. These regions overlapped with highly conserved domains. C53, a pol III-specific subunit, interacted with a 37-kDa polypeptide that copurifies with the enzyme and therefore appears to be a unique pol III subunit (C37). Together with parallel interaction studies based on dosage-dependent suppression of conditional mutants, our data suggest a model of the pol III preinitiation complex.
Service de Biochimie et Génétique Moléculaire, Bât. 142, Commissariat à l'Energie Atomique/Saclay, F-91191 Gif-sur-Yvette Cedex, France.
A
A
Flores
J F
JF
Briand
O
O
Gadal
J C
JC
Andrau
L
L
Rubbi
V
V
Van Mullem
C
C
Boschiero
M
M
Goussot
C
C
Marck
C
C
Carles
P
P
Thuriaux
A
A
Sentenac
M
M
Werner
D001665:Binding Sites; D017124:Conserved Sequence; D046911:Macromolecular Substances; D016366:Open Reading Frames; D019151:Peptide Library; D012318:RNA Polymerase I / Q000737:chemistry / Q000378:metabolism; D012319:RNA Polymerase II / Q000737:chemistry / Q000378:metabolism; D012320:RNA Polymerase III / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000737:chemistry; D012441:Saccharomyces cerevisiae / Q000201:enzymology* / Q000235:genetics; D014157:Transcription Factors / Q000737:chemistry / Q000378:metabolism; D019474:Transcription Factors, TFIII; D014158:Transcription, Genetic; D000098832:Transcription Factor TFIIIC
D046911:Macromolecular Substances; D019151:Peptide Library; D011993:Recombinant Fusion Proteins; D014157:Transcription Factors; D019474:Transcription Factors, TFIII; D000098832:Transcription Factor TFIIIC; D012319:RNA Polymerase II; D012318:RNA Polymerase I; D012320:RNA Polymerase III