3LTG CRYSTAL STRUCTURE OF THE DROSOPHILA EPIDERMAL GROWTH FACTOR RECEPTOR ECTODOMAIN COMPLEXED WITH A LOW AFFINITY SPITZ MUTANT TRANSFERASE/TRANSFERASE REGULATOR, RECEPTOR-LIGAND COMPLEX ECTODOMAIN CYSTEINE RICH DOMAIN EGF DOMAIN, ATP-BINDING, KINASE, NUCLEOTIDE-BINDING, RECEPTOR, TRANSFERASE, TYROSINE-PROTEIN KINASE, CELL MEMBRANE, DEVELOPMENTAL PROTEIN, DIFFERENTIATION, DISULFIDE BOND, EGF-LIKE DOMAIN, ENDOPLASMIC RETICULUM, GLYCOPROTEIN, GOLGI APPARATUS, MEMBRANE, NEUROGENESIS, TRANSMEMBRANE, TRANSFERASE-TRANSFERASE REGULATOR COMPLEX