4 (4 fluorophenyl) 2 (4 methylsulfinylphenyl) 5 (4 pyridyl)imidazole Amino Acid Sequence Amino Acid Substitution Catalytic Domain Conserved Sequence Crystallography, X-Ray Hydrogen Bonding Imidazoles Kinetics Leishmania major Mammalia Mitogen-Activated Protein Kinases Models, Molecular Molecular Sequence Data Mutagenesis, Site-Directed Protein Binding Protein Kinase Inhibitors Protein Structure, Secondary Protozoan Proteins Pyridines Sequence Homology, Amino Acid Structural Homology, Protein Thermodynamics Trypanosomatidae article carboxy terminal sequence catalysis crystal structure enzyme activation enzyme regulation