8DMX

Cryo-EM structure of skeletal muscle alpha-actin

Summary for 8DMX

• Entry DOI: 10.2210/pdb8dmx/pdb
• EMDB information: 27548
• Descriptor: Actin, alpha skeletal muscle, MAGNESIUM ION, ADENOSINE-5'-DIPHOSPHATE (3 entities in total)
• Functional Keywords: cytoskeleton, structural protein
• Biological source: Oryctolagus cuniculus (rabbit)
• Total number of polymer chains: 4
• Total formula weight: 169308.56

Authors

Arora, A.S.,Huang, H.L.,Heissler, S.M.,Chinthalapudi, K. (deposition date: 2022-07-08, release date: 2023-04-12)

Primary citation

Arora, A.S.,Huang, H.L.,Singh, R.,Narui, Y.,Suchenko, A.,Hatano, T.,Heissler, S.M.,Balasubramanian, M.K.,Chinthalapudi, K.
Structural insights into actin isoforms.
Elife, 12:-, 2023

PubMed Abstract: Actin isoforms organize into distinct networks that are essential for the normal function of eukaryotic cells. Despite a high level of sequence and structure conservation, subtle differences in their design principles determine the interaction with myosin motors and actin-binding proteins. Therefore, identifying how the structure of actin isoforms relates to function is important for our understanding of normal cytoskeletal physiology. Here, we report the high-resolution structures of filamentous skeletal muscle α-actin (3.37 Å), cardiac muscle α-actin (3.07 Å), ß-actin (2.99 Å), and γ-actin (3.38 Å) in the Mg·ADP state with their native post-translational modifications. The structures revealed isoform-specific conformations of the N-terminus that shift closer to the filament surface upon myosin binding, thereby establishing isoform-specific interfaces. Collectively, the structures of single-isotype, post-translationally modified bare skeletal muscle α-actin, cardiac muscle α-actin, ß-actin, and γ-actin reveal general principles, similarities, and differences between isoforms. They complement the repertoire of known actin structures and allow for a comprehensive understanding of in vitro and in vivo functions of actin isoforms.

PubMed: 36790143
DOI: 10.7554/eLife.82015

Experimental method

ELECTRON MICROSCOPY (3.37 Å)