Doniger J, Landsman D, Gonda M A, Wistow G
Department of Obstetrics and Gynecology, Georgetown University Medical Center, Washington, DC 20007.
New Biol. 1992 Apr;4(4):389-95.
We show that the open reading frame transcribed from the unr gene (immediately upstream of N-ras) in mammals consists of multiple repeats similar to the cold-shock domain (CSD), a putative DNA-binding motif found in prokaryotic cold-shock proteins, and eukaryotic DNA-binding proteins. Alignment of the CSD sequences of unr with those from other proteins reveals a core of similarity for which a consistent secondary structure prediction can be derived. This prediction suggests that the CSD consists primarily of beta-sheet, in contrast to most known eukaryotic DNA-binding proteins. Sequence analysis of the 3' end of the guinea pig unr gene shows that the core of one CSD repeat is encoded in a single exon, consistent with the modular assembly of the gene from ancestral CSD-coding units.
我们发现，哺乳动物中从unr基因（紧挨着N-ras上游）转录而来的开放阅读框由多个类似于冷休克结构域（CSD）的重复序列组成，冷休克结构域是一种在原核冷休克蛋白和真核DNA结合蛋白中发现的假定DNA结合基序。unr的CSD序列与其他蛋白的CSD序列比对揭示了一个相似性核心，由此可以得出一致的二级结构预测。该预测表明，与大多数已知的真核DNA结合蛋白不同，CSD主要由β-折叠组成。豚鼠unr基因3'端的序列分析表明，一个CSD重复序列的核心编码在一个外显子中，这与该基因由祖先CSD编码单元的模块化组装一致。
