[The role of sulfhydryl groups in the functioning of DNA-dependent RNA-polymerase].
Sulfhydryl groups of Escherichia coli DNA-dependent RNA polymerase were chemically modified with alkylating and mercuric-containing compounds. Iodoacetic acid and iodoacetamide were shown not to affect the enzymatic activity, whereas N-ethylmaleimide and mercuric-containing compounds completely inhibit the RNA synthesis. RNA polymerase modified with mercuric ions looses the ability of binding with promoter--containing DNA fragments. Moreover, mercuric ions inhibit the RNA elongation stage. Suggestion is made the Cys residues of RNA polymerase play a key role in double-stranded DNA unwinding. It is shown that SH-groups of beta- and beta'-subunits participate in the binding with double-stranded fragments of DNA.
O Iu
OIu
Chertov
O A
OA
Seliuchenko
V M
VM
Lipkin
D055598:Chemical Phenomena; D002621:Chemistry; D003545:Cysteine / Q000378:metabolism; D012321:DNA-Directed RNA Polymerases / Q000378:metabolism*; D004591:Electrophoresis, Polyacrylamide Gel; D004926:Escherichia coli / Q000201:enzymology; D010084:Oxidation-Reduction; D011485:Protein Binding; D012329:RNA, Bacterial / Q000096:biosynthesis; D013438:Sulfhydryl Compounds / Q000378:metabolism*; D013698:Templates, Genetic
D012329:RNA, Bacterial; D013438:Sulfhydryl Compounds; D012321:DNA-Directed RNA Polymerases; D003545:Cysteine
Rol' sul'fgidril'nykh grupp v funktsionirovanii DNK-zavisimoĭ RNK-polimerazy.