Myosin subfragment 1 structures reveal a partially bound nucleotide and a complex salt bridge that helps couple nucleotide and actin binding.Risal, D., Gourinath, S., Himmel, D.M., Szent-Gyorgyi, A.G., Cohen, C.
(2004) Proc.Natl.Acad.Sci.Usa 101: 8930-8935
- PubMed: 15184651
- DOI: 10.1073/pnas.0403002101
- Primary Citation of Related Structures:
- PubMed Abstract:
- Crystallographic findings on the internally uncoupled and near-rigor states of myosin: further insights into the mechanics of the motor
Himmel, D.M.,Gourinath, S.,Reshetnikova, L.,Shen, Y.,Szent-Gyorgyi, A.G.,Cohen, C.
(2002) Proc.Natl.Acad.Sci.USA 99: 12645
- Crystal structure of scallop Myosin s1 in the pre-power stroke state to 2.6 a resolution: flexibility and function in the head
Gourinath, S.,Himmel, D.M.,Brown, J.H.,Reshetnikova, L.,Szent-Gyorgyi, A.G.,Cohen, C.
(2003) Structure 11: 1621
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 s ...
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.
Rosenstiel Basic Medical Sciences Research Center, MS 029, Waltham, MA 02454-9110, USA.