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,bu...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.展开更多
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)+1 种基金the Ministry of Health of China(Grant No.2008ZX10404)CAS Research Grant(No.KSCX2-YW-R-127 and INFO-115-D01-2009).
文摘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.
