1SR6

Structure of nucleotide-free scallop myosin S1

1SR6 の概要

• エントリーDOI: 10.2210/pdb1sr6/pdb
• 関連するPDBエントリー: 1KK8 1QVI 1S5G
• 分子名称: Myosin heavy chain, striated muscle, Myosin regulatory light chain, striated adductor muscle, Myosin essential light chain, striated adductor muscle, ... (7 entities in total)
• 機能のキーワード: scallop myosin s1, near rigor, complex salt bridge, novel conformation of nucleotide, contractile protein
• 由来する生物種: Argopecten irradians; 詳細
• 細胞内の位置: Cytoplasm, myofibril: P24733
• タンパク質・核酸の鎖数: 3
• 化学式量合計: 131172.00

構造登録者

Risal, D.,Gourinath, S.,Himmel, D.M.,Szent-Gyorgyi, A.G.,Cohen, C. (登録日: 2004-03-22, 公開日: 2004-06-15, 最終更新日: 2023-08-23)

主引用文献

Risal, D.,Gourinath, S.,Himmel, D.M.,Szent-Gyorgyi, A.G.,Cohen, C.
Myosin subfragment 1 structures reveal a partially bound nucleotide and a complex salt bridge that helps couple nucleotide and actin binding.
Proc.Natl.Acad.Sci.Usa, 101:8930-8935, 2004

PubMed Abstract: Structural studies of myosin have indicated some of the conformational changes that occur in this protein during the contractile cycle, and we have now observed a conformational change in a bound nucleotide as well. The 3.1-A x-ray structure of the scallop myosin head domain (subfragment 1) in the ADP-bound near-rigor state (lever arm =45 degrees to the helical actin axis) shows the diphosphate moiety positioned on the surface of the nucleotide-binding pocket, rather than deep within it as had been observed previously. This conformation strongly suggests a specific mode of entry and exit of the nucleotide from the nucleotide-binding pocket through the so-called "front door." In addition, using a variety of scallop structures, including a relatively high-resolution 2.75-A nucleotide-free near-rigor structure, we have identified a conserved complex salt bridge connecting the 50-kDa upper and N-terminal subdomains. This salt bridge is present only in crystal structures of muscle myosin isoforms that exhibit a strong reciprocal relationship (also known as coupling) between actin and nucleotide affinity.

PubMed: 15184651
DOI: 10.1073/pnas.0403002101

実験手法

X-RAY DIFFRACTION (2.75 Å)