7NEP

Homology model of the in situ actomyosin complex from the A-band of mouse psoas muscle sarcomere in the rigor state

Summary for 7NEP

• Entry DOI: 10.2210/pdb7nep/pdb
• EMDB information: 12289
• Descriptor: Actin, alpha skeletal muscle, Tropomyosin alpha-1 chain, Myosin-4, ... (5 entities in total)
• Functional Keywords: muscle proteins, force generation, sarcomere, cytoskeleton, motor protein
• Biological source: Mus musculus (Mouse); More
• Total number of polymer chains: 21
• Total formula weight: 825747.62

Authors

Wang, Z.,Grange, M.,Wagner, T.,Kho, A.L.,Gautel, M.,Raunser, S. (deposition date: 2021-02-04, release date: 2021-04-07, Last modification date: 2024-05-01)

Primary citation

Wang, Z.,Grange, M.,Wagner, T.,Kho, A.L.,Gautel, M.,Raunser, S.
The molecular basis for sarcomere organization in vertebrate skeletal muscle.
Cell, 184:2135-, 2021

PubMed Abstract: Sarcomeres are force-generating and load-bearing devices of muscles. A precise molecular picture of how sarcomeres are built underpins understanding their role in health and disease. Here, we determine the molecular architecture of native vertebrate skeletal sarcomeres by electron cryo-tomography. Our reconstruction reveals molecular details of the three-dimensional organization and interaction of actin and myosin in the A-band, I-band, and Z-disc and demonstrates that α-actinin cross-links antiparallel actin filaments by forming doublets with 6-nm spacing. Structures of myosin, tropomyosin, and actin at ~10 Å further reveal two conformations of the "double-head" myosin, where the flexible orientation of the lever arm and light chains enable myosin not only to interact with the same actin filament, but also to split between two actin filaments. Our results provide unexpected insights into the fundamental organization of vertebrate skeletal muscle and serve as a strong foundation for future investigations of muscle diseases.

PubMed: 33765442
DOI: 10.1016/j.cell.2021.02.047

Experimental method

ELECTRON MICROSCOPY (10.2 Å)