hemoglobin complex / oxygen carrier activity / oxygen binding / response to hypoxia / iron ion binding / heme binding / extracellular region / metal ion binding 類似検索 - 分子機能
Annelid erythrocruorin linker subunit, C-terminal / Erythrocruorin linker subunit, C-terminal superfamily / Extracellular hemoglobin linker subunit, heterodimerisation domain / Annelid erythrocruorin linker subunit C-terminus / Globin, extracellular / Erythrocruorin / Low-density lipoprotein receptor domain class A / Myoglobin-like, M family globin domain / Low-density lipoprotein (LDL) receptor class A, conserved site / LDL-receptor class A (LDLRA) domain signature. ...Annelid erythrocruorin linker subunit, C-terminal / Erythrocruorin linker subunit, C-terminal superfamily / Extracellular hemoglobin linker subunit, heterodimerisation domain / Annelid erythrocruorin linker subunit C-terminus / Globin, extracellular / Erythrocruorin / Low-density lipoprotein receptor domain class A / Myoglobin-like, M family globin domain / Low-density lipoprotein (LDL) receptor class A, conserved site / LDL-receptor class A (LDLRA) domain signature. / LDL-receptor class A (LDLRA) domain profile. / Low-density lipoprotein receptor domain class A / Low-density lipoprotein (LDL) receptor class A repeat / LDL receptor-like superfamily / Globin/Protoglobin / Globin domain profile. / Globin / Globin / Globin-like superfamily 類似検索 - ドメイン・相同性
ジャーナル: IUCrJ / 年: 2017 タイトル: Single-particle cryo-EM using alignment by classification (ABC): the structure of haemoglobin. 著者: Pavel Afanasyev / Charlotte Seer-Linnemayr / Raimond B G Ravelli / Rishi Matadeen / Sacha De Carlo / Bart Alewijnse / Rodrigo V Portugal / Navraj S Pannu / Michael Schatz / Marin van Heel / 要旨: Single-particle cryogenic electron microscopy (cryo-EM) can now yield near-atomic resolution structures of biological complexes. However, the reference-based alignment algorithms commonly used in ...Single-particle cryogenic electron microscopy (cryo-EM) can now yield near-atomic resolution structures of biological complexes. However, the reference-based alignment algorithms commonly used in cryo-EM suffer from reference bias, limiting their applicability (also known as the 'Einstein from random noise' problem). Low-dose cryo-EM therefore requires robust and objective approaches to reveal the structural information contained in the extremely noisy data, especially when dealing with small structures. A reference-free pipeline is presented for obtaining near-atomic resolution three-dimensional reconstructions from heterogeneous ('four-dimensional') cryo-EM data sets. The methodologies integrated in this pipeline include camera correction, movie-based full-data-set contrast transfer function determination, movie-alignment algorithms, (Fourier-space) multivariate statistical data compression and unsupervised classification, 'random-startup' three-dimensional reconstructions, four-dimensional structural refinements and Fourier shell correlation criteria for evaluating anisotropic resolution. The procedures exclusively use information emerging from the data set itself, without external 'starting models'. Euler-angle assignments are performed by angular reconstitution rather than by the inherently slower projection-matching approaches. The comprehensive 'ABC-4D' pipeline is based on the two-dimensional reference-free 'alignment by classification' (ABC) approach, where similar images in similar orientations are grouped by unsupervised classification. Some fundamental differences between X-ray crystallography single-particle cryo-EM data collection and data processing are discussed. The structure of the giant haemoglobin from at a global resolution of ∼3.8 Å is presented as an example of the use of the ABC-4D procedure.
Reference-free Alignment By Classification (ABC-4D). Camera correction, CTF determination, particle-picking, MSA unsupervised classification, 3D reconstruction, all in IMAGIC-4D.
CTF補正
詳細: Phase flipping of micrograph patches (ctf2d-find)
最終 再構成
想定した対称性 - 点群: D6 (2回x6回 2面回転対称) アルゴリズム: OTHER / 解像度のタイプ: BY AUTHOR / 解像度: 3.8 Å / 解像度の算出法: OTHER / ソフトウェア - 名称: Imagic-4D / 使用した粒子像数: 85000