Template misalignment in multisubunit RNA polymerases and transcription fidelity.
Mol Cell
; 24(2): 257-66, 2006 Oct 20.
Article
em En
| MEDLINE
| ID: mdl-17052459
ABSTRACT
Recent work showed that the single-subunit T7 RNA polymerase (RNAP) can generate misincorporation errors by a mechanism that involves misalignment of the DNA template strand. Here, we show that the same mechanism can produce errors during transcription by the multisubunit yeast RNAP II and bacterial RNAPs. Fluorescence spectroscopy reveals a reorganization of the template strand during this process, and molecular modeling suggests an open space above the polymerase active site that could accommodate a misaligned base. Substrate competition assays indicate that template misalignment, not misincorporation, is the preferred mechanism for substitution errors by cellular RNAPs. Misalignment could account for data previously taken as evidence for additional NTP binding sites downstream of the active site. Analysis of the effects of different template topologies on misincorporation indicates that the duplex DNA immediately downstream of the active site plays an important role in transcription fidelity.
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Coleções:
01-internacional
Contexto em Saúde:
3_ND
Base de dados:
MEDLINE
Assunto principal:
Transcrição Gênica
/
Proteínas Virais
/
RNA Polimerases Dirigidas por DNA
Idioma:
En
Revista:
Mol Cell
Ano de publicação:
2006
Tipo de documento:
Article