7KOG

Lethocerus Myosin II complete coiled-coil domain resolved in its native environment

7KOG の概要

• エントリーDOI: 10.2210/pdb7kog/pdb
• EMDBエントリー: 22975 3301 7029
• 分子名称: Myosin heavy chain isoform Mhc_X1 (1 entity in total)
• 機能のキーワード: striated muscle, asynchronous flight muscle, motor protein
• 由来する生物種: Lethocerus indicus
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 450455.12

構造登録者

Rahmani, H.,Hu, Z.,Daneshparvar, N.,Taylor, D.,Taylor, K.A. (登録日: 2020-11-09, 公開日: 2021-03-24, 最終更新日: 2024-09-25)

主引用文献

Rahmani, H.,Ma, W.,Hu, Z.,Daneshparvar, N.,Taylor, D.W.,McCammon, J.A.,Irving, T.C.,Edwards, R.J.,Taylor, K.A.
The myosin II coiled-coil domain atomic structure in its native environment.
Proc.Natl.Acad.Sci.USA, 118:-, 2021

PubMed Abstract: The atomic structure of the complete myosin tail within thick filaments isolated from flight muscle is described and compared to crystal structures of recombinant, human cardiac myosin tail segments. Overall, the agreement is good with three exceptions: the proximal S2, in which the filament has heads attached but the crystal structure doesn't, and skip regions 2 and 4. At the head-tail junction, the tail α-helices are asymmetrically structured encompassing well-defined unfolding of 12 residues for one myosin tail, ∼4 residues of the other, and different degrees of α-helix unwinding for both tail α-helices, thereby providing an atomic resolution description of coiled-coil "uncoiling" at the head-tail junction. Asymmetry is observed in the nonhelical C termini; one C-terminal segment is intercalated between ribbons of myosin tails, the other apparently terminating at Skip 4 of another myosin tail. Between skip residues, crystal and filament structures agree well. Skips 1 and 3 also agree well and show the expected α-helix unwinding and coiled-coil untwisting in response to skip residue insertion. Skips 2 and 4 are different. Skip 2 is accommodated in an unusual manner through an increase in α-helix radius and corresponding reduction in rise/residue. Skip 4 remains helical in one chain, with the other chain unfolded, apparently influenced by the acidic myosin C terminus. The atomic model may shed some light on thick filament mechanosensing and is a step in understanding the complex roles that thick filaments of all species undergo during muscle contraction.

PubMed: 33782130
DOI: 10.1073/pnas.2024151118

実験手法

ELECTRON MICROSCOPY (4.25 Å)