Open AccessCrystallization and preliminary X‐ray analysis of the mRNA‐binding domain of elongation factor SelB from Escherichia coli in complex with RNA
Author(s) -
Soler Nicolas,
Fourmy Dominique,
Yoshizawa Satoko
Publication year - 2007
Publication title -
acta crystallographica section f
Language(s) - English
Resource type - Journals
ISSN - 1744-3091
DOI - 10.1107/s174430910701723x
Subject(s) - elongation factor , rna , biology , crystallography , transfer rna , ef tu , crystallization , selenocysteine , amino acid , messenger rna , biochemistry , chemistry , ribosome , gene , enzyme , cysteine , organic chemistry
In bacteria, selenocysteine (the 21st amino acid) is incorporated into proteins via machinery that includes SelB, a specific translational elongation factor. SelB binds to an mRNA hairpin called the selenocysteine‐insertion sequence (SECIS) and delivers selenocysteyl‐tRNA Sec to the ribosomal A site. The minimum C‐terminal fragment (residues 478–614) of Escherichia coli SelB (SelB‐WH3/4) required for SECIS binding has been overexpressed and purified. This protein was crystallized in complex with 23 nucleotides of the SECIS hairpin at 294 K using the hanging‐drop vapour‐diffusion method. A data set was collected to 2.3 Å resolution from a single crystal at 100 K using ESRF beamline BM‐30. The crystal belongs to space group C 2, with unit‐cell parameters a = 103.50, b = 56.51, c = 48.41 Å. The asymmetric unit contains one WH3/4‐domain–RNA complex. The Matthews coefficient was calculated to be 3.37 Å 3 Da −1 and the solvent content was estimated to be 67.4%.