3o3k

Publication Abstract from PubMed

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 A 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 (DeltaF(anom)/F) of 1.39% for 1.9 A wavelength X-rays. Coupled with an average Bijvoet redundancy of 25 (two 360 degrees 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 A resolution (PDB entry 3o3k). High-resolution data were subsequently collected from a better diffracting crystal using 0.97 A wavelength synchrotron X-rays and the S-SAD model was refined (R = 17.9%, R(free) = 21.4%) to 1.85 A 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.

Structure of the Archaeoglobus fulgidus orphan ORF AF1382 determined by sulfur SAD from a moderately diffracting crystal.,Zhu JY, Fu ZQ, Chen L, Xu H, Chrzas J, Rose J, Wang BC Acta Crystallogr D Biol Crystallogr. 2012 Sep;68(Pt 9):1242-52. Epub 2012 Aug 18. PMID:22948926^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.