Factors and nucleotide sequences that direct ribosomal DNA transcription and their relationship to the stable transcription complex.
AUTOR(ES)
Tower, J
RESUMO
We have studied the protein components and nucleic acid sequences involved in stably activating the ribosomal DNA (rDNA) template and in directing accurate transcription of mammalian rRNA genes. Two protein components are necessary to catalyze rDNA transcription, and these have been extensively purified. The first, factor D, can stably associate by itself with the rDNA promoter region and is responsible for template commitment. The second component, factor C, which appears to be an activated subset of polymerase I, can stably bind to the factor D-rDNA complex but not to the rDNA in the absence of factor D. A third component which had been previously identified as a rDNA transcription factor is shown to be a RNase inhibitor. Extending our earlier observation that the approximately 150-base-pair mouse rDNA promoter consists of a minimal essential region (residues approximately -35 to approximately +9) and additional upstream stimulatory domains, we now report that each of these promoter domains acts to augment the binding of the polymerase I transcription factors. A minimum core region (residues approximately -35 to approximately -15) is capable of stable complex formation and of binding transcription factor D. Factor C can also bind to this D-core region complex.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=367093Documentos Relacionados
- Characterization of factors that direct transcription of rat ribosomal DNA.
- Ribosomal RNA transcription: proteins and DNA sequences involved in preinitiation complex formation.
- Evolutionary changes of sequences and factors that direct transcription termination of human and mouse ribsomal genes.
- The Xenopus laevis ribosomal gene terminator contains sequences that both enhance and repress ribosomal transcription.
- Crosslinking transcription factors to their recognition sequences with PtII complexes.