Also MATTPROB indicates 3 or 4 molecules/asu as likely solutions. http://tinyurl.com/pe2choc
I do not understand why you propose 16 mol/asu? The entire unit cell would likely be only 8 molecules (2 tetramers).... BR -----Original Message----- From: CCP4 bulletin board [mailto:CCP4BB@JISCMAIL.AC.UK] On Behalf Of Remy Loris Sent: Sunday, August 17, 2014 4:45 AM To: CCP4BB@JISCMAIL.AC.UK Subject: [ccp4bb] A back of the envellope calculation shows that your asymmetric unit contains most likely 4 molecules with Vm = 2.16 A3/Da, corresponding to 43% solvent. Searching for 16 molecules is thus nonsense. Remy Loris Vrije Universiteit Brussel On 17/08/14 08:54, Avisek Mondal wrote: > Hello everyone, i am struggling with a problem.. My crystal was > diffracted at 1.9A in P21 spacegoup with unit cell parameter a=87.7 > > b=93.9, c=111.78 ,beta=94.98 which contains 16 molecules per > assymmetric unit (Molecular weight of the Protein+DNA =56 KDa. > > actually it is a complex of 40Kda tetramer and 23bpDNA ) .In solution, > it shows tetrameric in nature The crystal structure of its > > homologous structure has been reported earlier (50%identical in amino > acid seq.) and it was also a tetramer and its unit cell (also P21) > > was approximately 4 times less than mine. It showed 4 molecules per > assymmetric unit. I didn't get any molecular replacement. All > > the programms are takings very long time to do it. Although the single > crystal is untwinned i think it is a case of pseudosymmetry. > > Please help me if you have any good suggestion regarding molecular > replacement other than experimental phasing. >
