中国物理B ›› 2018, Vol. 27 ›› Issue (12): 128702-128702.doi: 10.1088/1674-1056/27/12/128702

• INTERDISCIPLINARY PHYSICS AND RELATED AREAS OF SCIENCE AND TECHNOLOGY • 上一篇    下一篇

The determinant factors for map resolutions obtained using CryoEM single particle imaging method

Yihua Wang(王义华), Daqi Yu(余大启), Qi Ouyang(欧阳颀), Haiguang Liu(刘海广)   

  1. 1 Key Laboratory for Artificial Microstructure and Mesoscopic Physics, Institute of Condensed Matter Physics, School of Physics, Center for Quantitative Biology School of Physics, The Peking-Tsinghua Center for Life Sciences at School of Physics, Peking University, Beijing 100084, China;
    2 Complex Systems Division, Beijing Computational Science Research Centre, Beijing 100193, China
  • 收稿日期:2018-07-12 修回日期:2018-10-08 出版日期:2018-12-05 发布日期:2018-12-05
  • 通讯作者: Haiguang Liu E-mail:hgliu@csrc.ac.cn
  • 基金资助:

    Project supported by the National Natural Science Foundation of China (Grant Nos. 11774011, 11434001, U1530401, and U1430237).

The determinant factors for map resolutions obtained using CryoEM single particle imaging method

Yihua Wang(王义华)1, Daqi Yu(余大启)1, Qi Ouyang(欧阳颀)1, Haiguang Liu(刘海广)2   

  1. 1 Key Laboratory for Artificial Microstructure and Mesoscopic Physics, Institute of Condensed Matter Physics, School of Physics, Center for Quantitative Biology School of Physics, The Peking-Tsinghua Center for Life Sciences at School of Physics, Peking University, Beijing 100084, China;
    2 Complex Systems Division, Beijing Computational Science Research Centre, Beijing 100193, China
  • Received:2018-07-12 Revised:2018-10-08 Online:2018-12-05 Published:2018-12-05
  • Contact: Haiguang Liu E-mail:hgliu@csrc.ac.cn
  • Supported by:

    Project supported by the National Natural Science Foundation of China (Grant Nos. 11774011, 11434001, U1530401, and U1430237).

摘要:

The CryoEM single particle structure determination method has recently received broad attention in the field of structural biology. The structures can be resolved to near-atomic resolutions after model reconstructions from a large number of CryoEM images measuring molecules in different orientations. However, the determining factors for reconstructed map resolution need to be further explored. Here, we provide a theoretical framework in conjunction with numerical simulations to gauge the influence of several key factors to CryoEM map resolutions. If the projection image quality allows orientation assignment, then the number of measured projection images and the quality of each measurement (quantified using average signal-to-noise ratio) can be combined to a single factor, which is dominant to the resolution of reconstructed maps. Furthermore, the intrinsic thermal motion of molecules has significant effects on the resolution. These effects can be quantitatively summarized with an analytical formula that provides a theoretical guideline on structure resolutions for given experimental measurements.

关键词: Cryo-EM, resolution, noise, conformation heterogeneity

Abstract:

The CryoEM single particle structure determination method has recently received broad attention in the field of structural biology. The structures can be resolved to near-atomic resolutions after model reconstructions from a large number of CryoEM images measuring molecules in different orientations. However, the determining factors for reconstructed map resolution need to be further explored. Here, we provide a theoretical framework in conjunction with numerical simulations to gauge the influence of several key factors to CryoEM map resolutions. If the projection image quality allows orientation assignment, then the number of measured projection images and the quality of each measurement (quantified using average signal-to-noise ratio) can be combined to a single factor, which is dominant to the resolution of reconstructed maps. Furthermore, the intrinsic thermal motion of molecules has significant effects on the resolution. These effects can be quantitatively summarized with an analytical formula that provides a theoretical guideline on structure resolutions for given experimental measurements.

Key words: Cryo-EM, resolution, noise, conformation heterogeneity

中图分类号:  (Electron microscopy)

  • 87.64.Ee
87.57.cf (Spatial resolution) 87.57.cm (Noise) 87.15.hp (Conformational changes)