National Institutes of Health/National Heart, Lung, and Blood Institute (NIH/NHLBI)
R01HL036153
United States
Citation
Journal: J Gen Physiol / Year: 2023 Title: Conformational changes linked to ADP release from human cardiac myosin bound to actin-tropomyosin. Authors: Matthew H Doran / Michael J Rynkiewicz / David Rasicci / Skylar M L Bodt / Meaghan E Barry / Esther Bullitt / Christopher M Yengo / Jeffrey R Moore / William Lehman / Abstract: Following binding to the thin filament, β-cardiac myosin couples ATP-hydrolysis to conformational rearrangements in the myosin motor that drive myofilament sliding and cardiac ventricular ...Following binding to the thin filament, β-cardiac myosin couples ATP-hydrolysis to conformational rearrangements in the myosin motor that drive myofilament sliding and cardiac ventricular contraction. However, key features of the cardiac-specific actin-myosin interaction remain uncertain, including the structural effect of ADP release from myosin, which is rate-limiting during force generation. In fact, ADP release slows under experimental load or in the intact heart due to the afterload, thereby adjusting cardiac muscle power output to meet physiological demands. To further elucidate the structural basis of this fundamental process, we used a combination of cryo-EM reconstruction methodologies to determine structures of the human cardiac actin-myosin-tropomyosin filament complex at better than 3.4 Å-resolution in the presence and in the absence of Mg2+·ADP. Focused refinements of the myosin motor head and its essential light chains in these reconstructions reveal that small changes in the nucleotide-binding site are coupled to significant rigid body movements of the myosin converter domain and a 16-degree lever arm swing. Our structures provide a mechanistic framework to understand the effect of ADP binding and release on human cardiac β-myosin, and offer insights into the force-sensing mechanism displayed by the cardiac myosin motor.
Entire : Complex of the human beta cardiac myosin II in the rigor form wit...
Entire
Name: Complex of the human beta cardiac myosin II in the rigor form with the associated essential light chain.
Components
Complex: Complex of the human beta cardiac myosin II in the rigor form with the associated essential light chain.
Complex: Human beta-cardiac myosin II
Protein or peptide: Beta-cardiac myosin II
Complex: Mouse skeletal essential light chain
Protein or peptide: Myosin light chain 1/3, skeletal muscle isoform
-
Supramolecule #1: Complex of the human beta cardiac myosin II in the rigor form wit...
Supramolecule
Name: Complex of the human beta cardiac myosin II in the rigor form with the associated essential light chain. type: complex / ID: 1 / Parent: 0 / Macromolecule list: all
-
Supramolecule #2: Human beta-cardiac myosin II
Supramolecule
Name: Human beta-cardiac myosin II / type: complex / ID: 2 / Parent: 1 / Macromolecule list: #1
Model: Quantifoil R1.2/1.3 / Material: GOLD / Mesh: 400 / Support film - Material: GOLD / Support film - topology: HOLEY / Pretreatment - Type: GLOW DISCHARGE / Pretreatment - Time: 30 sec. Details: 15 mA was used in the Pelco Easiglow glow discharge machine
Vitrification
Cryogen name: ETHANE / Chamber humidity: 100 % / Chamber temperature: 283 K / Instrument: FEI VITROBOT MARK III
Details
This complex was part of a larger filament containing actin-tropomyosin. The map was a result of a focused single particle approach.
-
Electron microscopy
Microscope
FEI TITAN KRIOS
Specialist optics
Energy filter - Name: In-column Omega Filter / Energy filter - Slit width: 20 eV
Image recording
Film or detector model: GATAN K3 (6k x 4k) / Detector mode: COUNTING / Digitization - Frames/image: 1-35 / Number grids imaged: 4 / Number real images: 3961 / Average exposure time: 3.12 sec. / Average electron dose: 53.7 e/Å2
Electron beam
Acceleration voltage: 300 kV / Electron source: FIELD EMISSION GUN
In the structure databanks used in Yorodumi, some data are registered as the other names, "COVID-19 virus" and "2019-nCoV". Here are the details of the virus and the list of structure data.
Jan 31, 2019. EMDB accession codes are about to change! (news from PDBe EMDB page)
EMDB accession codes are about to change! (news from PDBe EMDB page)
The allocation of 4 digits for EMDB accession codes will soon come to an end. Whilst these codes will remain in use, new EMDB accession codes will include an additional digit and will expand incrementally as the available range of codes is exhausted. The current 4-digit format prefixed with “EMD-” (i.e. EMD-XXXX) will advance to a 5-digit format (i.e. EMD-XXXXX), and so on. It is currently estimated that the 4-digit codes will be depleted around Spring 2019, at which point the 5-digit format will come into force.
The EM Navigator/Yorodumi systems omit the EMD- prefix.
Related info.:Q: What is EMD? / ID/Accession-code notation in Yorodumi/EM Navigator
Yorodumi is a browser for structure data from EMDB, PDB, SASBDB, etc.
This page is also the successor to EM Navigator detail page, and also detail information page/front-end page for Omokage search.
The word "yorodu" (or yorozu) is an old Japanese word meaning "ten thousand". "mi" (miru) is to see.
Related info.:EMDB / PDB / SASBDB / Comparison of 3 databanks / Yorodumi Search / Aug 31, 2016. New EM Navigator & Yorodumi / Yorodumi Papers / Jmol/JSmol / Function and homology information / Changes in new EM Navigator and Yorodumi