Affinity labeling of RNA-polymerase II in the transcriptionally active complex by a phosphorylating analog of the initiation substrate.
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.
Savinkova
L K
LK
Institute of Cytology and Genetics, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, 630090, Russia. savsok@niboch.nsc.ru
Sokolenko
A A
AA
Rau
V A
VA
Arshinova
T V
TV
Gerasimova
Y V
YV
Kudryashova
N V
NV
Godovikova
T S
TS
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
D000345:Affinity Labels; D012331:RNA, Fungal; D014157:Transcription Factors; D015761:4-Aminopyridine; D012319:RNA Polymerase II; C003885:4-dimethylaminopyridine