Polymerase(redirected from DNA-directed RNA polymerase)
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(nucleotidyltransferase), an enzyme of the transferase class that catalyzes the synthesis of nucleic acids from nucleoside triphosphates in the presence of DNA or RNA, which serves as the template. The synthesis of a new chain of DNA (replication) or RNA (transcription) on a DNA template is accomplished with strict adherence to the principle of complementarity.
The action of polymerases involves the transfer of a molecule of ribonucleoside or deoxyribonucleoside triphosphate to the end of a chain of RNA or DNA that is being synthesized, which results in extension of the chain and liberation of a molecule of pyrophosphate. The synthesis of RNA catalyzed by DNA-dependent RNA polymerase takes place on one of the chains of the double—helical DNA template. The newly synthesized polyribonucleotide branches from the DNA template as a single thread. The synthesis of DNA takes place simultaneously on both chains of a previously uncoiled DNA template.
The discovery and isolation of DNA polymerase in 1956 by the American scientist A. Romberg enabled him to be the first to carry out the synthesis of active DNA in a test tube.
REFERENCESKornberg, A. “Puti fermentativnogo sinteza nukleotidov i polinukleotidov.” In Khimicheskie osnovy nasledstvennosti. Moscovi 1960. (Translated from English.)
Davidson, J. Biokhimiia nukleinovykh kislot. Moscow, 1968. (Translated from English.)
L. S. KHAILOVA