Crystal structure of a novel non-Pfam protein PF2046 solved using low resolution B-factor sharpening and multi-crystal averaging methods  

作　　者：Jing Su Yang Li Neil Shaw Weihong Zhou Min Zhang Hao Xu Bi-Cheng Wang Zhi-Jie Liu 

机构地区：[1]National Laboratory of Biomacromolecules,Institute of Biophysics,Chinese Academy of Sciences,Beijing 100101,China [2]College of Life Sciences,Nankai University,Tianjin 300071,China [3]School of Life Sciences,Anhui University,Hefei 230039,China [4]Department of Biochemistry and Molecular Biology,University of Georgia,Atlanta,GA 30605,USA

出　　处：《Protein & Cell》2010年第5期453-458,共6页蛋白质与细胞（英文版）

基　　金：This work was funded by the Ministry of Science and Technology of China(Grant Nos.2006AA02A316,2009DFB30310 and 2006CB910901);the National Natural Science Foundation of China(Grants Nos.30670427 and 30721003);the Ministry of Health of China(Grant No.2008ZX10404);CAS Research Grant(No.KSCX2-YW-R-127 and INFO-115-D01-2009).

摘　　要：Sometimes crystals cannot diffract X-rays beyond 3.0Åresolution 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 3.38Åresolution.A combination of SeMet 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(R_(free)=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.

关 键 词：low resolution diffraction PF2046 Bfactor sharpening a homodimer of trimers 

分 类 号：O57[理学—粒子物理与原子核物理]