Transcriptional properties of BmX, a moderately repetitive silkworm gene that is an RNA polymerase III template.
AUTOR(ES)
Wilson, E T
RESUMO
We analyzed the transcriptional properties of a repetitive sequence element, BmX, that belongs to a large gene family (approximately 2 x 10(4) copies) in the genome of the Bombyx mori silkworm. We discovered BmX elements because of their ability to direct transcription by polymerase III in vitro and used them to test the generality of the properties of previously identified silkworm polymerase III control elements. We found that the signals that act in cis to control BmX transcription strongly resemble those that direct transcription of other silkworm polymerase III templates. As with silkworm tRNA and 5S RNA genes, transcription of BmX requires sequence signals located both upstream and downstream from the site of transcription initiation. The critical upstream sequences are structurally as well as functionally similar in the three kinds of templates. The downstream control region of BmX resembles the corresponding part of a silkworm alanine tRNA gene in that it provides a large (greater than 100 base pairs) region that influences transcription factor binding. Moreover, the factor-binding regions of both tRNA(Ala) and BmX genes are remarkable in that under certain conditions, key elements within them (the B boxes, for example) appear dispensable. This behavior can be understood if, in both of these templates, the downstream control region acts as a large target for interaction with a multifactor complex.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=363188Documentos Relacionados
- RRN3 gene of Saccharomyces cerevisiae encodes an essential RNA polymerase I transcription factor which interacts with the polymerase independently of DNA template.
- T7 RNA polymerase cannot transcribe through a highly knotted DNA template.
- Coronavirus mRNA transcription: UV light transcriptional mapping studies suggest an early requirement for a genomic-length template.
- RNA chain elongation on a chromatin template.
- Gyration is required for 5S RNA transcription from a chromatin template.