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首页> 外文期刊>Acta crystallographica.Section D. Biological crystallography >OASIS and molecular-replacement model completion
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OASIS and molecular-replacement model completion

机译：绿洲和molecular-replacement模型完成

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A method of dual-space molecular-replacement model completion has been proposed which involves the programs ARP/wARP, REFMAC, OASIS and DM. OASIS is used in reciprocal space for phase refinement based on models built by ARP/wARP. For this purpose, the direct-method probability formula of breaking SAD/SIR phase ambiguities has been redefined. During the phase refinement, phi(h)'' in the expression phi(h)'' = phi(h)''+/-vertical bar Delta phi(h)vertical bar is redefined as a reference phase calculated from a randomly selected 5% of the atoms in the current structure model, while vertical bar Delta phi(h)vertical bar is defined as the absolute difference between the phase of the current model and phi(h)''. The probability formula P (+)(Delta phi(h))= 1/2 + 1/2 tanh {sin vertical bar Delta phi(h)vertical bar x [Sigma(h)m(h)m(h) - (h ')kappa(h,h ') sin (Phi(3)' + Delta phi(h ' best) + Delta phi(h-h ' best)) + chi sin delta(h)]} is then used to derive the sign of Delta phi(h). In this way the '0-2 pi' phase problem is reduced to a 'plus or minus' sign problem. The redefinition implies that during the refinement phases close to the true values will probably be kept unchanged, while those distant from the true values will probably undergo a large shift. This is the desired property of phase refinement. The procedure has been tested using protein diffraction data without SAD/SIR signals. The results show that dual-space MR-model completion making use of OASIS is much more efficient than that without.
机译：一种对偶空间方法molecular-replacement模型提出了包括完成项目ARP /扭曲,REFMAC、绿洲和DM,绿洲在倒易空间用于细化阶段基于模型由ARP /变形。目的,直接法的概率公式打破悲伤/先生阶段模棱两可重新定义。在表达φ(h)”=φ(h)“+ /垂直酒吧δφ(h)重新定义为一个竖线引用从一个随机相位计算选择5%的原子在当前的结构模型,而竖线δφ(h)垂直酒吧被定义为绝对的区别当前模型的阶段和φ(h)”。概率公式P(+)(δφ(h)) = 1/2 +1/2双曲正切{罪竖线δφ(h)垂直酒吧x(σ(h) m (h) m (h) - (h)卡帕(h, h)罪(Phi值(3)‘非(h + d组‘百)+ d组Phi值(h-h’最好的)+气罪δ(h)]}然后使用得到δφ(h)的符号。“0 - 2π”阶段的问题是“加或减少-信号问题。在细化阶段接近真正的值可能会保持不变,而那些远离真正的值可能经历一个大的转变。需要细化阶段的属性。过程已经使用蛋白质进行了测试衍射数据不难过/爵士的信号。结果表明,对偶空间MR-model完成利用绿洲更有效,没有。

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