Localisation of the binding site for the initiating substrate on the RNA polymerase from Sulfolobus acidocaldarius.
RNA polymerase from the archaebacterium Sulfolobus acidocaldarius was chemically modified with AMP o-formylphenyl ester followed by reduction with borohydride. The modified protein catalyzes the labeling of its own largest subunit when incubated with [alpha-33P]UTP in the presence of poly[d(A-T)]. On cleaving of the labeled protein using cyanogen bromide, hydroxylamine or amino acid-specific endoproteinases for a very brief period, the pattern and size of the radioactive fragments formed are best explained by attachment of the label between Gly843 and Met895 of the largest subunit. In this region there exists a highly conserved sequence which is also found in other archaebacterial, eukaryotic and prokaryotic RNA polymerase. This suggests that the binding site for the initiating substrate of RNA polymerases has been conserved during evolution.
Grachev
M A
MA
Limnological Institute, Siberian Division of the Academy of Sciences of the USSR, Irkutsk.
Mustaev
A A
AA
Zaychikov
E F
EF
Lindner
A J
AJ
Hartmann
G R
GR
D000345:Affinity Labels; D000595:Amino Acid Sequence; D001105:Archaea / Q000201:enzymology*; D001419:Bacteria / Q000201:enzymology*; D001665:Binding Sites; D012321:DNA-Directed RNA Polymerases / Q000378:metabolism*; D004591:Electrophoresis, Polyacrylamide Gel; D006868:Hydrolysis; D007700:Kinetics; D008969:Molecular Sequence Data; D013045:Species Specificity; D013379:Substrate Specificity
D000345:Affinity Labels; D012321:DNA-Directed RNA Polymerases