On the subunit composition, stoichiometry, and phosphorylation of the yeast transcription factor TFIIIC/tau.
Saccharomyces cerevisiae transcription factor IIIC/tau is a multisubunit DNA-binding protein that plays key roles in tRNA and 5 S rRNA gene activation. Subunit composition, stoichiometry, and in vivo phosphorylation of TFIIIC/tau factor were investigated using factor prepared from strains carrying modified forms of TFC1, the gene encoding the 95-kDa TFIIIC/tau subunit (tau 95). Using an epitope-tagged TFC1 as well as a TFC1-lacZ fusion, TFIIIC was shown to contain a single 95-kDa subunit, which was localized by electron microscopy into tau A, the A block-binding domain of TFIIIC/tau. Three 35S-labeled polypeptides (at 138, 131, and 91 kDa) coimmunoprecipitated with a tau 95-beta-galactosidase fusion protein. The coprecipitation of the 91-kDa polypeptide makes it a likely subunit of the factor. Immunoprecipitation from 32P-labeled extracts revealed that three of the subunits (138, 131, and 95 kDa), but not the 91-kDa component, are phosphorylated in vivo.
Conesa
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C
Service de Biochimie et Génétique Moléculaire, Centre d'Etudes de Saclay, Gif sur Yvette, France.
Swanson
R N
RN
Schultz
P
P
Oudet
P
P
Sentenac
A
A
D001483:Base Sequence; D001665:Binding Sites; D004591:Electrophoresis, Polyacrylamide Gel; D000939:Epitopes / Q000032:analysis; D005800:Genes, Fungal; D007700:Kinetics; D046911:Macromolecular Substances; D008854:Microscopy, Electron; D008969:Molecular Sequence Data; D008970:Molecular Weight; D016297:Mutagenesis, Site-Directed; D009838:Oligodeoxyribonucleotides; D010761:Phosphorus Radioisotopes; D010766:Phosphorylation; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism*; D013462:Sulfur Radioisotopes; D014157:Transcription Factors / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D019474:Transcription Factors, TFIII; D014158:Transcription, Genetic; D001616:beta-Galactosidase / Q000235:genetics / Q000378:metabolism; D000098832:Transcription Factor TFIIIC
D000939:Epitopes; D046911:Macromolecular Substances; D009838:Oligodeoxyribonucleotides; D010761:Phosphorus Radioisotopes; D011993:Recombinant Fusion Proteins; D013462:Sulfur Radioisotopes; D014157:Transcription Factors; D019474:Transcription Factors, TFIII; D000098832:Transcription Factor TFIIIC; D001616:beta-Galactosidase