A first low-resolution difference Fourier map of phosphorus in a membrane protein from near-edge anomalous diffraction.
Crystal diffraction of three membrane proteins (cytochrome bc(1) complex, sarcoplasmic reticulum Ca(2+) ATPase, ADP-ATP carrier) and of one nucleoprotein complex (leucyl tRNA synthetase bound to tRNAleu, leuRS:tRNAleu) was tested at wavelengths near the X-ray K-absorption edge of phosphorus using a new set-up for soft X-ray diffraction at the beamline ID01 of the ESRF. The best result was obtained from crystals of Ca(2+) ATPase [adenosin-5'-(beta,gamma-methylene) triphosphate complex] which diffracted out to 7 A resolution. Data were recorded at a wavelength at which the real resonant scattering factor of phosphorus reaches the extreme value of -20 electron units. The positions of the four triphosphates of the monoclinic unit cell of the ATPase have been obtained from a difference Fourier synthesis based on a limited set of anomalous diffraction data.
Boesecke
Peter
P
ESRF, F-38043 Grenoble, France.
Bois
Jean Marie
JM
Crépin
Thibaut
T
Hunte
Carola
C
Kahn
Richard
R
Kao
Wei Chun
WC
Nauton
Lionel
L
Winther
Anne Marie Lund
AM
Moller
Jesper
J
Nissen
Poul
P
Nury
Hughes
H
Olesen
Claus
C
Pebay-Peyroula
Eva
E
Vicat
Jean
J
Stuhrmann
Heinrich
H
D018360:Crystallography, X-Ray / Q000379:methods*; D005583:Fourier Analysis; D008565:Membrane Proteins / Q000737:chemistry*; D010758:Phosphorus / Q000032:analysis*
D008565:Membrane Proteins; D010758:Phosphorus