An W, van Holde K, Zlatanova J
Department of Biochemistry and Biophysics, Oregon State University, Corvallis, OR 97331-7305, USA.
Nucleic Acids Res. 1998 Sep 1;26(17):4042-6. doi: 10.1093/nar/26.17.4042.
The location of the linker histone (LH) on the nucleosome has been the subject of recent controversy. Although previous evidence had supported a location over the dyad axis, some recent experiments suggest an asymmetric, off-axis position. In this paper we show that the DNA sequence used to reconstitute chromatosomes in these experiments is prone to artifacts in nuclease digestion: results interpreted as 'protection' by LHs can be obtained with either naked DNA or with reconstituted core nucleosomes, in the absence of LHs. Consequently, we feel that general interpretation or extrapolation of such results must be regarded with the utmost caution. In addition, we show that the protection data on an alternative, previously unreported major core position on this same DNA sequence support a model of asymmetric, off-axis position of the LH, with linker DNA protection on only one side of the core particle.
连接组蛋白（LH）在核小体上的定位一直是近期争论的焦点。尽管先前的证据支持其位于二分体轴上，但最近的一些实验表明它处于不对称的离轴位置。在本文中，我们表明在这些实验中用于重构染色质小体的DNA序列在核酸酶消化时容易产生假象：在没有LH的情况下，无论是裸露的DNA还是重构的核心核小体都能得到被解释为LH“保护”的结果。因此，我们认为对这类结果进行一般性解释或外推时必须极其谨慎。此外，我们表明关于该相同DNA序列上另一个先前未报道的主要核心位置的保护数据支持LH不对称离轴位置的模型，即连接DNA仅在核心颗粒的一侧受到保护。
