Tyler B M, Giles N H
Nucleic Acids Res. 1985 Jun 25;13(12):4311-32. doi: 10.1093/nar/13.12.4311.
A Neurospora in vitro transcription system has been developed which specifically and efficiently initiates transcription of a cloned Neurospora crassa ribosomal RNA gene by RNA polymerase I. The initiation site of transcription (both in vitro and in vivo) appears to be located about 850 bp from the 5' end of mature 17S rRNA. However, the primary rRNA transcripts are normally cleaved very rapidly at a site 120-125 nt from the 5' end in vitro and in vivo. The nucleotide sequence surrounding the initiation site has been determined. The region from -16 to +9 exhibits partial homology to the corresponding sequences from a wide variety of organisms including yeast, but the most striking similarity is to the initiation region from Dictyostelium discoideum which displays 73% homology to the Neurospora sequence from -23 to +47. The Neurospora sequences from -96 to +97 have been shown to be sufficient for transcription. This region contains two sequences displaying 8/9 bp matches to elements of the 5S rDNA promoter.
已开发出一种粗糙脉孢菌体外转录系统，该系统能特异性且高效地通过RNA聚合酶I起始克隆的粗糙脉孢菌核糖体RNA基因的转录。转录起始位点（无论体外还是体内）似乎位于距成熟17S rRNA 5'端约850 bp处。然而，初级rRNA转录本在体外和体内通常会在距5'端120 - 125 nt的位点迅速被切割。已确定起始位点周围的核苷酸序列。从 -16到 +9的区域与包括酵母在内的多种生物的相应序列具有部分同源性，但最显著的相似性是与盘基网柄菌的起始区域，该区域与粗糙脉孢菌从 -23到 +47的序列显示出73%的同源性。已证明粗糙脉孢菌从 -96到 +97的序列足以进行转录。该区域包含两个与5S rDNA启动子元件显示8/9 bp匹配的序列。
