ジャーナル: Structure / 年: 2015 タイトル: Near-atomic resolution for one state of F-actin. 著者: Vitold E Galkin / Albina Orlova / Matthijn R Vos / Gunnar F Schröder / Edward H Egelman / 要旨: Actin functions as a helical polymer, F-actin, but attempts to build an atomic model for this filament have been hampered by the fact that the filament cannot be crystallized and by structural ...Actin functions as a helical polymer, F-actin, but attempts to build an atomic model for this filament have been hampered by the fact that the filament cannot be crystallized and by structural heterogeneity. We have used a direct electron detector, cryo-electron microscopy, and the forces imposed on actin filaments in thin films to reconstruct one state of the filament at 4.7 Å resolution, which allows for building a reliable pseudo-atomic model of F-actin. We also report a different state of the filament where actin protomers adopt a conformation observed in the crystal structure of the G-actin-profilin complex with an open ATP-binding cleft. Comparison of the two structural states provides insights into ATP-hydrolysis and filament dynamics. The atomic model provides a framework for understanding why every buried residue in actin has been under intense selective pressure.
らせん対称: (回転対称性: 1 / Dyad axis: no / N subunits divisor: 1 / Num. of operations: 10 / Rise per n subunits: 28.3 Å / Rotation per n subunits: -166.8 °)
詳細
Actin forms a helical filament of indeterminate length. The designation "decameric" in REMARK 350 is an artifact of the PDB format and can be disregarded.