Bartuv J, Valansi C, Shalitin C
Department of Biology, Technion-Israel Institute of Technology, Haifa.
Biochem Biophys Res Commun. 1993 Mar 15;191(2):750-8. doi: 10.1006/bbrc.1993.1281.
The aim of this study was to elucidate the function of Yp20 (yeast 20 kDa protein) which is an abundant basic DNA-binding protein copurified with yeast chromatin. The work presented here shows that Yp20 is a sequence specific DNA binding protein. DNA binding activity was extremely thermostable. The affinity of binding to TRP1 was higher than the affinity of binding to the B domain of ARS1. The dissociation half time of Yp20-DNA complexes was less than 1 min. Yp20 showed no homology to a similar abundant 21 kDa ARS binding factor II (ABFII), previously described. Competitive gel retardation assays revealed two different regions that were protected by Yp20. One was overlapping the ABF1 binding site on ARS1 and another protected region was found upstream to the translational start codon of the TRP1 gene. It thus appears that Yp20 may have a role in DNA replication and/or transcription.
本研究的目的是阐明Yp20（酵母20 kDa蛋白）的功能，该蛋白是一种与酵母染色质共纯化的丰富碱性DNA结合蛋白。此处展示的工作表明Yp20是一种序列特异性DNA结合蛋白。DNA结合活性具有极高的热稳定性。与TRP1的结合亲和力高于与ARS1的B结构域的结合亲和力。Yp20-DNA复合物的解离半衰期小于1分钟。Yp20与先前描述的类似丰富的21 kDa ARS结合因子II（ABFII）没有同源性。竞争性凝胶阻滞试验揭示了两个受Yp20保护的不同区域。一个与ARS1上的ABF1结合位点重叠，另一个受保护区域位于TRP1基因翻译起始密码子的上游。因此，Yp20似乎可能在DNA复制和/或转录中发挥作用。
