Myosin V motors regulate secretion and cell division in eukaryotes. How MyoV activity is differentially regulated by essential and calmodulin light chain binding remains unclear. We have used NMR spectroscopy to compare the dynamic behavior of Mlc1p, a budding yeast essential light chain, with that of the Xenopus laevis calmodulin. Both proteins have a similar structure and bind similar target proteins but differ in the mechanism by which they interact with the myosin V IQ1. This interaction is essential for MyoV activity. Here, we show that the rigid conformation of the loop connecting the two EF-hand motifs of the Mlc1p N-lobe explains its differential ability to interact with myosin V IQ1. Moreover, we show that the maintenance of the N-lobe structure is required for the essential function of Mlc1p in vivo. These data show that the core characteristics of myosin light chain N-lobes differentiate Mlc1p and calmodulin binding capability.
|Evidence ID||Analyze ID||Interactor||Interactor Systematic Name||Interactor||Interactor Systematic Name||Type||Assay||Annotation||Action||Modification||Phenotype||Source||Reference||Note|
|Evidence ID||Analyze ID||Gene||Gene Systematic Name||Gene Ontology Term||Gene Ontology Term ID||Qualifier||Aspect||Method||Evidence||Source||Assigned On||Annotation Extension||Reference|
|Evidence ID||Analyze ID||Gene||Gene Systematic Name||Phenotype||Experiment Type||Experiment Type Category||Mutant Information||Strain Background||Chemical||Details||Reference|
|Evidence ID||Analyze ID||Regulator||Regulator Systematic Name||Target||Target Systematic Name||Experiment||Assay||Construct||Conditions||Strain Background||Reference|