Three-dimensional structure of vertebrate cardiac muscle myosin filaments

• DOI: 10.1073/pnas.0708912105
• Publication Date: 2008-02-06T02:09:03Z
• Authors: Maria E. Zoghbi; John L. Woodhead; Richard L. Moss; Roger Craig
• Keywords: Meromyosin; Myofibril; Myofilament; Cardiac muscle

Contraction of the heart results from interaction myosin and actin filaments. Cardiac filaments consist molecular motor II, sarcomeric template protein, titin, cardiac modulatory binding protein C (MyBP-C). Inherited hypertrophic cardiomyopathy (HCM) is a disease caused mainly by mutations in these proteins. The structure alterations HCM are unknown. We have used electron microscopy image analysis to determine three-dimensional wild-type mouse muscle MyBP-C knockout model for HCM. Three-dimensional reconstruction filament reveals conformation heads organization titin at 4 nm resolution. Myosin appear interact with each other intramolecularly, as off-state smooth [Wendt T, Taylor D, Trybus KM, K (2001) Proc Natl Acad Sci USA 98:4361-4366], suggesting that all relaxed IIs may adopt this conformation. Titin domains run an elongated strand along surface, where they part backbone. In filament, some head interactions disrupted, important normal relaxation filament. These observations provide key insights into role contraction, assembly, disease. techniques we developed should be useful studying structural basis myosin-related diseases.