title: Purification and properties of Saccharomyces cerevisiae RNA polymerase II general initiation factor a.
abstract: RNA polymerase II initiation factor a was purified to apparent homogeneity from yeast whole cell extract and consisted of two highly charged polypeptides with apparent masses of 66 and 43 kDa. Separation and renaturation of the subunits showed that both were required for transcription activity. The native mass of factor a was estimated to be 240-260 kDa by gel filtration, but its sedimentation rate in a glycerol gradient was similar to that of a much smaller globular protein, suggesting an extended conformation. Factor a was required for utilization of six different eukaryotic promoters in vitro, indicating a general role in promoter-directed transcription by yeast RNA polymerase II.
authors.affiliation: Department of Cell Biology, Stanford University School of Medicine, California 94305.
authors.forename: M H
authors.initials: MH
authors.lastname: Sayre
authors.forename: H
authors.initials: H
authors.lastname: Tschochner
authors.forename: R D
authors.initials: RD
authors.lastname: Kornberg
mesh_terms: D002499:Centrifugation, Density Gradient; D002846:Chromatography, Affinity; D002850:Chromatography, Gel; D002851:Chromatography, High Pressure Liquid; D007700:Kinetics; D046911:Macromolecular Substances; D008970:Molecular Weight; D011487:Protein Conformation; D012319:RNA Polymerase II / Q000302:isolation & purification* / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000201:enzymology / Q000378:metabolism*; D014157:Transcription Factors / Q000302:isolation & purification / Q000378:metabolism*
chemical_list: D046911:Macromolecular Substances; D014157:Transcription Factors; D012319:RNA Polymerase II