Functional regions in the essential light chain of smooth muscle myosin as revealed by the mutagenesis approach.
The endogenous essential light chain (LC17) of myosin from intestine smooth muscle was replaced with mutated essential light chains prepared using recombinant techniques. Complete exchange was observed with histidine-tagged derivatives of LC17a, LC17b and E122A-LC17a (LC17a and LC17b are the usual constituants of smooth muscle myosin), with small changes in the ATPase activity of reconstituted myosins. Much less exchange was observed with the light-chain derivative lacking the last 12 amino acid residues, demonstrating the importance of this segment, which may act as one arm of a pair of pincers to bind the myosin heavy chain.
Quevillon-Chéruel
S
S
Laboratoire des Gènes et Protéines Musculaires, Université de Paris-Sud, France. sophie.cheruel@egm.u-psud.fr
Janmot
C
C
Nozais
M
M
Lompré
A M
AM
Béchet
J J
JJ
D000595:Amino Acid Sequence; D000818:Animals; D017301:Ca(2+) Mg(2+)-ATPase / Q000378:metabolism; D003106:Colon / Q000378:metabolism; D006639:Histidine; D007583:Jejunum / Q000378:metabolism; D008969:Molecular Sequence Data; D009130:Muscle, Smooth / Q000378:metabolism*; D016297:Mutagenesis, Site-Directed; D018994:Myosin Light Chains / Q000737:chemistry* / Q000378:metabolism*; D009218:Myosins / Q000737:chemistry / Q000378:metabolism; D020033:Protein Isoforms / Q000737:chemistry / Q000378:metabolism; D011817:Rabbits; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism
D018994:Myosin Light Chains; D020033:Protein Isoforms; D011994:Recombinant Proteins; D006639:Histidine; D017301:Ca(2+) Mg(2+)-ATPase; D009218:Myosins