Mutational analysis of differences in thermostability between histones from mesophilic and hyperthermophilic archaea.
Mutational analysis of differences in thermostability between histones from mesophilic and hyperthermophilic archaea.
复制标题
嗜温和超嗜热古菌组蛋白之间热稳定性差异的突变分析。
DOI：
10.1128/jb.182.3.812-817.2000
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发表时间：
2000
影响因子：
3.2
通讯作者：
Reeve,JN
中科院分区：
文献类型：
--
作者：
Li,WT;Shriver,JW;Reeve,JN
通过位点特异性诱变，研究人员鉴定出了HMfB和HFoB之间热稳定性差异的氨基酸残基，这些氨基酸残基分别来自超嗜热的嗜热emethanothermus fervidus和嗜热的甲酸emethanobacterium formicicum。通过圆二色性监测了~ 70种古菌组蛋白变体的热变性，并将生成的数据拟合到两态展开模型（二聚体→两个随机线圈单体），以获得每种变体二聚体的标准状态（1M）熔化温度。单、双和三残基取代的结果表明，相对于rHFoB二聚体，rHMfB二聚体的稳定性要高得多，这主要是由于组蛋白二聚体核心中心附近分子间疏水相互作用的改善以及二聚体表面额外的有利离子对。
Amino acid residues responsible for the large difference in thermostability between HMfB and HFoB, archaeal histones from the hyperthermophileMethanothermus fervidusand the mesophileMethanobacterium formicicum, respectively, have been identified by site-specific mutagenesis. The thermal denaturation of ∼70 archaeal histone variants has been monitored by circular dichroism, and the data generated were fit to a two-state unfolding model (dimer→two random coil monomers) to obtain a standard-state (1M) melting temperature for each variant dimer. The results of single-, double-, and triple-residue substitutions reveal that the much higher stability of rHMfB dimers, relative to rHFoB dimers, is conferred predominantly by improved intermolecular hydrophobic interactions near the center of the histone dimer core and by additional favorable ion pairs on the dimer surface.