Direct structure refinement against residual dipolar couplings in the presence of rhombicity of unknown magnitude
Direct structure refinement against residual dipolar couplings in the presence of rhombicity of unknown magnitude
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DOI：
10.1006/jmre.1997.1345
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发表时间：
1998-03-01
影响因子：
2.2
通讯作者：
Tjandra, N
中科院分区：
文献类型：
--
作者：
Clore, GM;Gronenborn, AM;Tjandra, N
由于分子在磁场中的小排列程度而产生的残余偶极耦合提供了独特的长期结构信息，最近对于磁化率张量是轴对称的蛋白质-DNA复合体，这种方法的潜力已经被证明，但是对于大多数大分子和大分子复合体，不能假设轴对称。此外，显著菱形的存在将明显影响所得到的坐标的精度。在这篇通讯中，我们提出了一种简单的计算策略，该策略利用模拟退火法对剩余偶极耦合进行精化，并结合网格搜索，同时精化结构并确定张量的轴向和菱形分量的大小。
Residual dipolar couplings arising from small degrees of alignment of molecules in a magnetic field provide unique long-range structural information, The potential of this approach for structure refinement has recently been demonstrated for a protein-DNA complex in which the magnetic susceptibility tensor was axially symmetric, For most macromolecules and macromolecular complexes, however, axial symmetry cannot be assumed. Moreover, the presence of significant rhombicity will clearly affect the accuracy of the resulting coordinates. In this Communication we present a simple calculational strategy that makes use of simulated annealing refinement against the residual dipolar couplings in combination with a grid search, to simultaneously refine the structures and ascertain the magnitude of the axial and rhombic components of the tensor.