GroEL-GroES complex / mitochondrial unfolded protein response / chaperonin ATPase / protein import into mitochondrial intermembrane space / virion assembly / chaperone cofactor-dependent protein refolding / positive regulation of interferon-alpha production / isomerase activity / ATP-dependent protein folding chaperone / response to radiation ...GroEL-GroES complex / mitochondrial unfolded protein response / chaperonin ATPase / protein import into mitochondrial intermembrane space / virion assembly / chaperone cofactor-dependent protein refolding / positive regulation of interferon-alpha production / isomerase activity / ATP-dependent protein folding chaperone / response to radiation / positive regulation of interleukin-6 production / positive regulation of type II interferon production / unfolded protein binding / positive regulation of T cell activation / フォールディング / protein-folding chaperone binding / response to heat / protein refolding / magnesium ion binding / ATP hydrolysis activity / ATP binding / 生体膜 / identical protein binding / 細胞質基質 類似検索 - 分子機能
ジャーナル: Structure / 年: 2008 タイトル: De novo backbone trace of GroEL from single particle electron cryomicroscopy. 著者: Steven J Ludtke / Matthew L Baker / Dong-Hua Chen / Jiu-Li Song / David T Chuang / Wah Chiu / 要旨: In this work, we employ single-particle electron cryo-microscopy (cryo-EM) to reconstruct GroEL to approximately 4 A resolution with both D7 and C7 symmetry. Using a newly developed skeletonization ...In this work, we employ single-particle electron cryo-microscopy (cryo-EM) to reconstruct GroEL to approximately 4 A resolution with both D7 and C7 symmetry. Using a newly developed skeletonization algorithm and secondary structure element identification in combination with sequence-based secondary structure prediction, we demonstrate that it is possible to achieve a de novo Calpha trace directly from a cryo-EM reconstruction. The topology of our backbone trace is completely accurate, though subtle alterations illustrate significant differences from existing crystal structures. In the map with C7 symmetry, the seven monomers in each ring are identical; however, the subunits have a subtly different structure in each ring, particularly in the equatorial domain. These differences include an asymmetric salt bridge, density in the nucleotide-binding pocket of only one ring, and small shifts in alpha helix positions. This asymmetric conformation is different from previous asymmetric structures, including GroES-bound GroEL, and may represent a "primed state" in the chaperonin pathway.