must occur before synthesis of the 3 ..

The increase in rRNA promoter activity in the nusB5 mutant is accompanied by a parallel derepression of synthesis of tRNAs that are not encoded by rRNA operons.

Antitermination of transcription from an Escherichia coli ribosomal RNA promoter.

Wu H, Yang PK, Butcher SE, et al. (2001) A novel family of RNA tetraloop structure forms the recognition site for Saccharomyces cerevisiae RNase III. EMBO Journal 20: 7240–7249.


A regulatory RNA required for antitermination of …

Isolation of conditionally lethal amber mutations affecting synthesis of the nusA protein of Escherichia coli.

Structural mapping studies revealed tRNA Gly -induced protection in the glyQS leader RNA at the two known sites of interaction with the tRNA, as well as at other regions between these sites.


What is the function of single stranded RNA in certain ..

N2 - The first step in the replication of influenza virion RNAs is the synthesis of full-length transcripts of these RNAs. The synthesis of these transcripts, or template RNAs, requires: (i) unprimed initiation rather than the capped RNA-primed initiation used during viral mRNA synthesis, and (ii) antitermination at the polyadenylylation site used during mRNA synthesis. To determine the mechanism of template RNA synthesis, we prepared nuclear extracts from infected cells that were active in the synthesis of both template RNAs and viral mRNAs. By providing the dinucleotide ApG as primer, we circumvented the inefficient unprimed initiation catalyzed by these extracts and, as a consequence, were able to focus on the antitermination step. Antitermination, and hence template RNA synthesis, occurred when ApG but not a capped RNA was used as primer, indicating that the presence of a 5' capped end blocked antitermination at the 3' end of the transcript. Ultracentrifugation of the nuclear extract yielded a pellet fraction that contained viral nucleocapsids active in viral mRNA synthesis but not template RNA synthesis and a supernatant fraction that contained the antitermination factor. When the supernatant, which had essentially no activity by itself, was added to the pellet in the presence of ApG, template RNA synthesis was restored. Depletion experiments in which this supernatant was incubated with protein A-Sepharose containing antibodies to individual viral proteins demonstrated that the viral nucleocapsid protein was required for antitermination. The implications of these results for the control of viral RNA replication are discussed.

Lambda λ antitermination protein N ..

Correll CC, Munishkin A, Chan YL, et al. (1998) Crystal structure of the ribosomal RNA domain essential for binding elongation factors. Proceedings of the National Academy of Sciences of the United States of America 95: 13436–13441.

Transcription and RNA Processing Flashcards | Quizlet

AB - The first step in the replication of influenza virion RNAs is the synthesis of full-length transcripts of these RNAs. The synthesis of these transcripts, or template RNAs, requires: (i) unprimed initiation rather than the capped RNA-primed initiation used during viral mRNA synthesis, and (ii) antitermination at the polyadenylylation site used during mRNA synthesis. To determine the mechanism of template RNA synthesis, we prepared nuclear extracts from infected cells that were active in the synthesis of both template RNAs and viral mRNAs. By providing the dinucleotide ApG as primer, we circumvented the inefficient unprimed initiation catalyzed by these extracts and, as a consequence, were able to focus on the antitermination step. Antitermination, and hence template RNA synthesis, occurred when ApG but not a capped RNA was used as primer, indicating that the presence of a 5' capped end blocked antitermination at the 3' end of the transcript. Ultracentrifugation of the nuclear extract yielded a pellet fraction that contained viral nucleocapsids active in viral mRNA synthesis but not template RNA synthesis and a supernatant fraction that contained the antitermination factor. When the supernatant, which had essentially no activity by itself, was added to the pellet in the presence of ApG, template RNA synthesis was restored. Depletion experiments in which this supernatant was incubated with protein A-Sepharose containing antibodies to individual viral proteins demonstrated that the viral nucleocapsid protein was required for antitermination. The implications of these results for the control of viral RNA replication are discussed.