%A Jing Su, Yang Li, Neil Shaw, Weihong Zhou, Min Zhang, Hao Xu, Bi-Cheng Wang, Zhi-Jie Liu %T Crystal structure of a novel non-Pfam protein PF2046 solved using low resolution B-factor sharpening and multi-crystal averaging methods %0 Journal Article %D 2010 %J Protein Cell %J Protein & Cell %@ 1674-800X %R 10.1007/s13238-010-0045-7 %P 453-458 %V 1 %N 5 %U {https://journal.hep.com.cn/pac/EN/10.1007/s13238-010-0045-7 %8 2010-05-01 %X

Sometimes crystals cannot diffract X-rays beyond 3.0 ? resolution due to the intrinsic flexibility associated with the protein. Low resolution diffraction data not only pose a challenge to structure determination, but also hamper interpretation of mechanistic details. Crystals of a 25.6 kDa non-Pfam, hypothetical protein, PF2046, diffracted X-rays to 3.38 ? resolution. A combination of Se-Met derived heavy atom positions with multiple cycles of B-factor sharpening, multi-crystal averaging, restrained refinement followed by manual inspection of electron density and model building resulted in a final model with a R value of 23.5 (Rfree=24.7). The asymmetric unit was large and consisted of six molecules arranged as a homodimer of trimers. Analysis of the structure revealed the presence of a RNA binding domain suggesting a role for PF2046 in the processing of nucleic acids.