TRANSFERASE, SER/THR KINASE, RGS HOMOLOGY DOMAIN, G PROTEIN COUPLED RECEPTOR KINASE, GRK, GRK1, RHODOPSIN KINASE, P-LOOP, AUTOPHOSPHORYLATION, ADP, ATP-BINDING, LIPOPROTEIN, MEMBRANE, METHYLATION, NUCLEOTIDE-BINDING, PHOSPHOPROTEIN, PRENYLATION, SERINE/THREONINE-PROTEIN KINASE 3C4Z CRYSTAL STRUCTURE OF G PROTEIN COUPLED RECEPTOR KINASE 1 BOUND TO ADP AND MAGNESIUM CHLORIDE AT 1.84A