1b7t
MYOSIN DIGESTED BY PAPAINMYOSIN DIGESTED BY PAPAIN
Structural highlights
Function[MYS_ARGIR] Muscle contraction. Myosin is a protein that binds to F-actin and has ATPase activity that is activated by F-actin. [MLE_ARGIR] In molluscan muscle, calcium regulation is associated with myosin rather than with actin. Muscle myosin contains two types of light chains: the catalytic light chain, essential for ATPase activity, and the regulatory light chain, a calcium-binding protein responsible for Ca(2+) dependent binding and Ca(2+) dependent Mg-ATPase activity. [MLR_ARGIR] In molluscan muscle, calcium regulation is associated with myosin rather than with actin. Muscle myosin contains two types of light chains: the catalytic light chain, essential for ATPase activity, and the regulatory light chain, a calcium-binding protein responsible for Ca(2+) dependent binding and Ca(2+) dependent Mg-ATPase activity. Evolutionary Conservation![]() Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedThe crystal structure of a proteolytic subfragment from scallop striated muscle myosin, complexed with MgADP, has been solved at 2.5 A resolution and reveals an unusual conformation of the myosin head. The converter and the lever arm are in very different positions from those in either the pre-power stroke or near-rigor state structures; moreover, in contrast to these structures, the SH1 helix is seen to be unwound. Here we compare the overall organization of the myosin head in these three states and show how the conformation of three flexible "joints" produces rearrangements of the four major subdomains in the myosin head with different bound nucleotides. We believe that this novel structure represents one of the prehydrolysis ("ATP") states of the contractile cycle in which the myosin heads stay detached from actin. Atomic structure of scallop myosin subfragment S1 complexed with MgADP: a novel conformation of the myosin head.,Houdusse A, Kalabokis VN, Himmel D, Szent-Gyorgyi AG, Cohen C Cell. 1999 May 14;97(4):459-70. PMID:10338210[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References |
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