RNA polymerase I


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RNA polymerase I

[¦är¦en¦ā pə¦lim·ə‚rās ′wən]
(cell and molecular biology)
An enzyme found in the nucleolus that copies ribosomal genes to produce ribosomal ribonucleic acid.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
References in periodicals archive ?
His research focuses on the mechanism of transcription by RNA polymerase I. RNA polymerase is an enzyme found in all living organizations.
John Donelson (University of Iowa, Iowa City, IA) reviewed antigenic variation in Trypanosoma bruce; and recent findings on the use of an extranucleolar body containing RNA polymerase I to regulate expression of VSG genes.
Once the RNA polymerase is bound to its specific sites in the DNA, it starts synthesizing the messenger RNA (mRNA) by copying one strand of the DNA.
In vitro transcription using T7 RNA polymerase is also often used to assess the site-specific incorporation of unnatural bases into RNA.
When the T7 RNA polymerase is in the cytoplasm, it acts with high specific affinity upon unique T7 promoter sequences incorporated into the vector, resulting in the generation of RNA transcripts that encode additional T7 polymerase and a second gene of interest.
"The RNA polymerase is used to make new copies of the virus," Kawaoka says.