THE ALPHA-AMYLASE FROM THE YELLOW MEAL WORM - COMPLETE PRIMARY STRUCTURE, CRYSTALLIZATION AND PRELIMINARY-X-RAY ANALYSIS

The alpha-amylase from Tenebrio molitor larvae (TMA) was purified from a crude larval extract, After removal of the N-terminal pyroglutamate residue and identification of the following 17 residues by Edman sequ encing, the cDNA of mature TMA was cloned from larval mRNA, The encode d enzyme consists of 471 amino acid residues and has 57-79% sequence i dentity to other insect alpha-amylases and also shows high homology to the mammalian enzymes, TMA was crystallized in form of well-ordered o rthorhombic crystals of space group P2(1)2(1)2(1) diffracting beyond 1 .6 Angstrom resolution with unit cell dimensions of a = 51.24 Angstrom , b = 93.46 Angstrom, c = 96.95 Angstrom. TMA may serve as model syste m for the future analysis of interactions between insect alpha-amylase and proteinaceous plant inhibitors on the molecular level. (C) 1997 F ederation of European Biochemical Societies.