例如:"lncRNA", "apoptosis", "WRKY"

Structure of the Archaeoglobus fulgidus orphan ORF AF1382 determined by sulfur SAD from a moderately diffracting crystal.

Acta Crystallogr. D Biol. Crystallogr.2012 Sep;68(Pt 9):1242-52. Epub 2012 Aug 18
Jin-Yi Zhu 1 , Zheng-Qing Fu , Lirong Chen , Hao Xu , John Chrzas , John Rose , Bi-Cheng Wang
Jin-Yi Zhu 1 , Zheng-Qing Fu , Lirong Chen , Hao Xu , John Chrzas , John Rose , Bi-Cheng Wang
+ et al

[No authors listed]

Author information
  • 1 Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA 30602, USA.

摘要


The crystal structure of the 11.14 kDa orphan ORF 1382 from Archaeoglobus fulgidus (AF1382) has been determined by sulfur SAD phasing using a moderately diffracting crystal and 1.9 Å wavelength synchrotron X-rays. AF1382 was selected as a structural genomics target by the Southeast Collaboratory for Structural Genomics (SECSG) since sequence analyses showed that it did not belong to the Pfam-A database and thus could represent a novel fold. The structure was determined by exploiting longer wavelength X-rays and data redundancy to increase the anomalous signal in the data. AF1382 is a 95-residue protein containing five S atoms associated with four methionine residues and a single cysteine residue that yields a calculated Bijvoet ratio (ΔF(anom)/F) of 1.39% for 1.9 Å wavelength X-rays. Coupled with an average Bijvoet redundancy of 25 (two 360° data sets), this produced an excellent electron-density map that allowed 69 of the 95 residues to be automatically fitted. The S-SAD model was then manually completed and refined (R = 23.2%, R(free) = 26.8%) to 2.3 Å resolution (PDB entry 3o3k). High-resolution data were subsequently collected from a better diffracting crystal using 0.97 Å wavelength synchrotron X-rays and the S-SAD model was refined (R = 17.9%, R(free) = 21.4%) to 1.85 Å resolution (PDB entry 3ov8). AF1382 has a winged-helix-turn-helix structure common to many DNA-binding proteins and most closely resembles the N-terminal domain (residues 1-82) of the Rio2 kinase from A. fulgidus, which has been shown to bind DNA, and a number of MarR-family transcriptional regulators, suggesting a similar DNA-binding function for AF1382. The analysis also points out the advantage gained from carrying out data reduction and structure determination on-site while the crystal is still available for further data collection.