第1415回生物科学セミナー
Servalcatによるクライオ電子顕微鏡単粒子解析の構造精密化とマップ計算
山下 恵太郎 研究員（MRC Laboratory of Molecular Biology Postdoctoral Scientist）
2022年05月30日(月) 15:30-16:30 Zoomによるweb講義
In 2020, cryo-EM single particle analysis (SPA) achieved true atomic resolution, thanks to technological developments in hardware and software. The number of high resolution reconstructions continues to grow, increasing the importance of accurate determination of atomic coordinates. Here we present a new program Servalcat for the refinement and map calculation of cryo-EM SPA structures. Servalcat implements a refinement pipeline using REFMAC5, which uses a dedicated likelihood function for SPA. It takes as inputs unsharpened and unweighted half maps from independent reconstructions. The variance of noise in Fourier coefficients is estimated using the half maps. A weighted and sharpened Fo-Fc map is calculated after the refinement. This map helps manual model rebuilding in real space, as is common practice in crystallography. Servalcat is freely available under an open source licence github.com/keitaroyam/servalcat, and is also available as part of CCP-EM v1.6. The new version of Refmac5 with various updates for SPA is also available from CCP4 8.0.
担当：東京大学大学院理学系研究科・生物科学専攻・濡木理
