title: Affinity labeling of RNA-polymerase II in the transcriptionally active complex by a phosphorylating analog of the initiation substrate.
abstract: Affinity modification of RNA-polymerase II by a phosphorylating analog of the initiation substrate carrying a zwitterionic 5;-terminal phosphate group with a 4-N,N-dimethylaminopyridine residue (DMAP-pA) was studied during specific transcription initiation controlled by the late adenoviral promotor. Super-selective affinity labeling and standard conditions of affinity modification resulted in labeling a polypeptide with molecular weight corresponding to that of the third subunit of the enzyme, RPB3 (45 kD). The initiation substrate (ATP) protects RNA-polymerase II from modification. The third subunit may be involved in the formation of the substrate-binding site of the enzyme.
authors.affiliation: Institute of Cytology and Genetics, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, 630090, Russia. savsok@niboch.nsc.ru
authors.forename: L K
authors.initials: LK
authors.lastname: Savinkova
authors.forename: A A
authors.initials: AA
authors.lastname: Sokolenko
authors.forename: V A
authors.initials: VA
authors.lastname: Rau
authors.forename: T V
authors.initials: TV
authors.lastname: Arshinova
authors.forename: Y V
authors.initials: YV
authors.lastname: Gerasimova
authors.forename: N V
authors.initials: NV
authors.lastname: Kudryashova
authors.forename: T S
authors.initials: TS
authors.lastname: Godovikova
mesh_terms: D015761:4-Aminopyridine / Q000031:analogs & derivatives*; D000345:Affinity Labels; D001483:Base Sequence; D010766:Phosphorylation; D012319:RNA Polymerase II / Q000378:metabolism*; D012331:RNA, Fungal / Q000235:genetics / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000201:enzymology / Q000235:genetics; D013379:Substrate Specificity; D014157:Transcription Factors / Q000378:metabolism; D014158:Transcription, Genetic
chemical_list: D000345:Affinity Labels; D012331:RNA, Fungal; D014157:Transcription Factors; D015761:4-Aminopyridine; D012319:RNA Polymerase II; C003885:4-dimethylaminopyridine