Hi
I am trying to solve the structure of RNA polymerase in complex with its protein primer. The size of protein primer is 70 amino acids which i complexed with the polymerase and collected a data of the complex crysta at 2.3A. The space group is C2  and after Molecular replacemnet with full length polymerase in auto MR i got 3 subunits in ASU.
The parameters of MR solution  RFZ=71.5 TFZ=41.2 PAK=0 LLG=8812 suggests that the solution is correct. I used autobuild for model building which gave me the model of the polymerase as well as some extra density that i am considering as the other protein. After several round of refinemnt i have R and R free of 27and 32 respectively.
 
My queries:
 1. I want to know ,how can i improve my R as well as R free.
 2. How can i model  other protein as the density is weak and not complete, how can i improve the map of the other protein so that i can b ebale to trace the c-alpha backbone, i was able to model only 10 amino acids so far.
 
Please guide.
 
Regards
 
 
 
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INTEKHAB ALAM
LABORATORY OF STRUCTURAL BIOINFORMATICS
KOREA UNIVERSITY, SEOUL