title: Crystal structure of a novel non-Pfam protein PF2046 solved using low resolution B-factor sharpening and multi-crystal averaging methods.
abstract: Sometimes crystals cannot diffract X-rays beyond 3.0 Å 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 Å 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 (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.
authors.affiliation: National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Su
authors.forename: Yang
authors.initials: Y
authors.lastname: Li
authors.forename: Neil
authors.initials: N
authors.lastname: Shaw
authors.forename: Weihong
authors.initials: W
authors.lastname: Zhou
authors.forename: Min
authors.initials: M
authors.lastname: Zhang
authors.forename: Hao
authors.initials: H
authors.lastname: Xu
authors.forename: Bi-Cheng
authors.initials: BC
authors.lastname: Wang
authors.forename: Zhi-Jie
authors.initials: ZJ
authors.lastname: Liu
mesh_terms: D001426:Bacterial Proteins / Q000737:chemistry*; D018360:Crystallography, X-Ray; D008958:Models, Molecular; D011487:Protein Conformation; D020027:Pyrococcus furiosus / Q000737:chemistry*; D012995:Solubility
chemical_list: D001426:Bacterial Proteins