7MF3

Structure of the autoinhibited state of smooth muscle myosin-2

Summary for 7MF3

• Entry DOI: 10.2210/pdb7mf3/pdb
• EMDB information: 23810
• Descriptor: Myosin-11, Myosin light polypeptide 6, Myosin regulatory light chain 2, smooth muscle major isoform, ... (6 entities in total)
• Functional Keywords: muscle contraction, atpase, autoinhibition, 10s, contractile protein
• Biological source: Gallus gallus (Chicken); More
• Total number of polymer chains: 8
• Total formula weight: 990445.52

Authors

Heissler, S.M.,Arora, A.S.,Billington, N.,Sellers, J.R.,Chinthalapudi, K. (deposition date: 2021-04-08, release date: 2022-01-05, Last modification date: 2024-05-29)

Primary citation

Heissler, S.M.,Arora, A.S.,Billington, N.,Sellers, J.R.,Chinthalapudi, K.
Cryo-EM structure of the autoinhibited state of myosin-2.
Sci Adv, 7:eabk3273-eabk3273, 2021

PubMed Abstract: We solved the near-atomic resolution structure of smooth muscle myosin-2 in the autoinhibited state (10) using single-particle cryo–electron microscopy. The 3.4-Å structure reveals the precise molecular architecture of 10 and the structural basis for myosin-2 regulation. We reveal the position of the phosphorylation sites that control myosin autoinhibition and activation by phosphorylation of the regulatory light chain. Further, we present a previously unidentified conformational state in myosin-2 that traps ADP and P produced by the hydrolysis of ATP in the active site. This noncanonical state represents a branch of the myosin enzyme cycle and explains the autoinhibition of the enzyme function of 10 along with its reduced affinity for actin. Together, our structure defines the molecular mechanisms that drive 10 formation, stabilization, and relief by phosphorylation of the regulatory light chain.

PubMed: 34936462
DOI: 10.1126/sciadv.abk3273

Experimental method

ELECTRON MICROSCOPY (3.4 Å)