Architecture of the maize mitochondrial atp1 promoter as determined by linker-scanning and point mutagenesis.
AUTOR(ES)
Rapp, W D
RESUMO
Plant mitochondrial promoters are poorly conserved but generally share a loose consensus sequence spanning approximately 17 nucleotides. Using a homologous in vitro transcription system, we have previously shown that an 11-nucleotide sequence within this region comprises at least part of the maize mitochondrial atp1 promoter (W. Rapp and D. Stern, EMBO J. 11:1065-1073, 1992). We have extended this finding by using a series of linker-scanning and point mutations to define the atp1 promoter in detail. Our results show that mutations at positions -12 to +5, relative to the major transcription start site, can decrease initiation rates to between < 10 and 40% of wild-type levels. Some mutations, scattered throughout this region, have lesser effects or no effect. Taken together, our data suggest a model in which the atp1 promoter consists of a central domain extending from -7 to +5 and an upstream domain of 1 to 3 bp that is centered around -11 to -12. Because many mutations within this promoter region are tolerated in vitro, the maize atp1 promoter is distinct from the highly conserved yeast mitochondrial promoters.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=364793Documentos Relacionados
- Analysis of the rat ribosomal DNA promoter: characterization of linker-scanning mutants and of the binding of UBF.
- Analysis of the mouse Dhfr/Rep-3 major promoter region by using linker-scanning and internal deletion mutations and DNase I footprinting.
- Linker-scanning mutational analysis of the transcriptional activity of the human immunodeficiency virus type 1 long terminal repeat.
- Two distinct promoter elements in the human rRNA gene identified by linker scanning mutagenesis.
- A conserved 11 nucleotide sequence contains an essential promoter element of the maize mitochondrial atp1 gene.