Bernués J, Querol E
Institut de Biologia Fonamental V. Villar-Palasi, Universitat Autònoma de Barcelona, Spain.
Biochim Biophys Acta. 1989 Jun 1;1008(1):52-61. doi: 10.1016/0167-4781(89)90169-3.
We have studied how non-histone proteins HMG1 and HMG2 interact with rat liver chromatin using reconstitution and chemical cross-linking procedures. Both proteins were found to associate to chromatin only to some extent and always with a marked preference for short oligonucleosomes, mainly mono- and dinucleosomes. However, a slight reconstitution with the long polynucleosomal fraction can be observed in H1-depleted chromatin. Reconstitution is non-random and a clear preference for regions highly sensitive to staphylococcal nuclease (EC 3.1.31.1) is observed. Chemical cross-linking has allowed us to identify H1, H2A and H2B as the histones contacted by HMG1 and HMG2 upon reconstitution. Also, we present evidence that HMG1 and HMG2 interact with the nucleosomal particle without replacing H1 or any other histone.
我们利用重组和化学交联方法研究了非组蛋白HMG1和HMG2与大鼠肝脏染色质的相互作用。发现这两种蛋白质仅在一定程度上与染色质结合，并且总是明显偏好短寡核小体，主要是单核小体和双核小体。然而，在H1缺失的染色质中可以观察到与长多核小体部分的轻微重组。重组是非随机的，并且观察到对葡萄球菌核酸酶（EC 3.1.31.1）高度敏感的区域有明显偏好。化学交联使我们能够鉴定出H1、H2A和H2B是重组时与HMG1和HMG2接触的组蛋白。此外，我们提供证据表明HMG1和HMG2与核小体颗粒相互作用而不取代H1或任何其他组蛋白。
