Zheng R, Ghirlando R, Lee M S, Mizuuchi K, Krause M, Craigie R
Laboratory of Molecular Biology, National Institute of Diabetes, and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA.
Proc Natl Acad Sci U S A. 2000 Aug 1;97(16):8997-9002. doi: 10.1073/pnas.150240197.
Barrier-to-autointegration factor (BAF) is a highly conserved cellular protein that was identified by its activity in protecting retroviral DNA against autointegration. We show that BAF has the property of bridging double-stranded DNA in a highly ordered nucleoprotein complex. Whereas BAF protein alone is a dimer in solution, upon binding DNA, BAF forms a dodecamer with DNA bound at multiple discrete sites in the complex. The interactions between BAF and DNA are entirely nonspecific with respect to DNA sequence. The dual interaction of BAF with DNA and LAP2, a protein associated with the nuclear lamina, suggests a role for LAP2 in chromosome organization. Consistent with this idea, RNA interference experiments with Caenorhabditis elegans reveal a defect in mitosis.
自身整合屏障因子（BAF）是一种高度保守的细胞蛋白，它通过保护逆转录病毒DNA免受自身整合的活性而被鉴定出来。我们发现BAF具有在高度有序的核蛋白复合物中桥连双链DNA的特性。虽然单独的BAF蛋白在溶液中是二聚体，但在结合DNA后，BAF会形成一个十二聚体，DNA在复合物中的多个离散位点结合。BAF与DNA之间的相互作用在DNA序列方面完全是非特异性的。BAF与DNA以及与核纤层相关的蛋白LAP2之间的双重相互作用表明LAP2在染色体组织中发挥作用。与这一观点一致，秀丽隐杆线虫的RNA干扰实验揭示了有丝分裂中的缺陷。
