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.
