Identification and description of beta-structure in horse muscle acylphosphatase by nuclear magnetic resonance spectroscopy.
Nuclear magnetic resonance spectra of acylphosphatase were searched for signs of beta-structure, i.e. characteristic nuclear Overhauser enhancement patterns displayed in the two-dimensional spectra, typical chemical shifts, coupling constants and slow 2H-H exchange. The results provided identification of the main-chain resonances of amino acid residues involved in the beta-structure. The full sequential assignment of this region was gained by identification of some amino acid spin systems and their alignment with the primary sequence. The assignment of the side-chains was virtually completed subsequently and a list produced of nuclear magnetic resonance (n.m.r.) constraints derived from the spectra. The beta-structure consists of a beta-sheet with four antiparallel chains, one attached parallel chain, three tight turns and a beta-bulge. The conformation of the beta-sheet was determined by distance geometry calculation using the n.m.r. constraints (174 intraresidual, 107 sequential and 226 long-range distances, 32 torsion angles, phi, and 28 hydrogen bonds) as input. Observation of some interactions between the sheet and previously identified alpha-helical regions made it possible to give an outline of the three-dimensional structure of the enzyme.
Saudek
V
V
Inorganic Chemistry Laboratory, University of Oxford, U.K.
Wormald
M R
MR
Williams
R J
RJ
Boyd
J
J
Stefani
M
M
Ramponi
G
G
D017766:Acid Anhydride Hydrolases; D000595:Amino Acid Sequence; D000596:Amino Acids; D000818:Animals; D006736:Horses; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D008961:Models, Structural; D008969:Molecular Sequence Data; D009132:Muscles / Q000201:enzymology*; D010744:Phosphoric Monoester Hydrolases; D011487:Protein Conformation; D000097024:Acylphosphatase
D017766:Acid Anhydride Hydrolases; D000596:Amino Acids; D010744:Phosphoric Monoester Hydrolases; D000097024:Acylphosphatase