3BAT

Crystal structure of the N-terminal region of the scallop myosin rod, monoclinic (P21) form

Summary for 3BAT

• Entry DOI: 10.2210/pdb3bat/pdb
• Related: 1NKN 3BAS
• Descriptor: Myosin heavy chain, striated muscle/General control protein GCN4 (2 entities in total)
• Functional Keywords: alpha-helical coiled coil, disorder, salt links, contractile protein, actin-binding, atp-binding, calmodulin-binding, cytoplasm, motor protein, muscle protein, myosin, nucleotide-binding, thick filament
• Biological source: Argopecten irradians (, baker's yeast); More
• Cellular location: Nucleus: P03069
• Total number of polymer chains: 4
• Total formula weight: 42236.70

Authors

Brown, J.H.,Cohen, C. (deposition date: 2007-11-08, release date: 2008-01-08, Last modification date: 2023-08-30)

Primary citation

Brown, J.H.,Yang, Y.,Reshetnikova, L.,Gourinath, S.,Suveges, D.,Kardos, J.,Hobor, F.,Reutzel, R.,Nyitray, L.,Cohen, C.
An unstable head-rod junction may promote folding into the compact off-state conformation of regulated myosins.
J.Mol.Biol., 375:1434-1443, 2008

PubMed Abstract: The N-terminal region of myosin's rod-like subfragment 2 (S2) joins the two heads of this dimeric molecule and is key to its function. Previously, a crystal structure of this predominantly coiled-coil region was determined for a short fragment (51 residues plus a leucine zipper) of the scallop striated muscle myosin isoform. In that study, the N-terminal 10-14 residues were found to be disordered. We have now determined the structure of the same scallop peptide in three additional crystal environments. In each of two of these structures, improved order has allowed visualization of the entire N-terminus in one chain of the dimeric peptide. We have also compared the melting temperatures of this scallop S2 peptide with those of analogous peptides from three other isoforms. Taken together, these experiments, along with examination of sequences, point to a diminished stability of the N-terminal region of S2 in regulated myosins, compared with those myosins whose regulation is thin filament linked. It seems plain that this isoform-specific instability promotes the off-state conformation of the heads in regulated myosins. We also discuss how myosin isoforms with varied thermal stabilities share the basic capacity to transmit force efficiently in order to produce contraction in their on states.

PubMed: 18155233
DOI: 10.1016/j.jmb.2007.11.071

Experimental method

X-RAY DIFFRACTION (2.3 Å)