@ Jim Me neither, i should read before i reply, my fault.
Tobias On 30 Apr 2014, at 17:15, Jim Pflugrath <jim.pflugr...@rigaku.com> wrote: > The anomalous signal will always come from both Ca and S and any other atoms > in the crystal. One can determine whether an anomalous difference Fourier > peak is from a sulfur on a cysteine, methionine from the model, right? As > for whether a peak that is not part of an amino acid id Ca++ or Sulfur, one > can use their knowledge of chemistry. > > I myself have never seen a separate peak that was a single sulfur atom. > > Jim > > From: CCP4 bulletin board [CCP4BB@JISCMAIL.AC.UK] on behalf of Faisal Tarique > [faisaltari...@gmail.com] > Sent: Wednesday, April 30, 2014 7:01 AM > To: CCP4BB@JISCMAIL.AC.UK > Subject: [ccp4bb] anomalous signal > > Dear all > > I am working on a metalloprotein which probably contains Ca at its active > site..The sulfur containing amino acid constitutes almost 5.4% of the total > amino acid residues of this protein..I have collected the data at home source > (CuKalpha=1.54A)..Since f'' of Sulfur is 0.56 and that of Ca is 1.28 we can > always expect some anomalous signal out of the data..My question is ..how we > will know if the anomalous signal is coming out of Sulfur or from Calcium ?? > is there any method through which we can get to know the identity of the > scattering molecule through the data..Can FFT anomalous map from CCP4 is of > any help in this direction, if yes then please tell me how to interpret the > output from this.. > > -- > Regards > > Faisal > School of Life Sciences > JNU
