Crystallization and preliminary X-ray diffraction analysis of anEscherichia colitRNA^Glyacceptor-stem microhelix

Abstract

The tRNAGly and glycyl-tRNA synthetase (GlyRS) system is an evolutionary special case within the class II aminoacyl-tRNA synthetases because two divergent types of GlyRS exist: an archaebacterial/human type and an eubacterial type. The tRNA identity elements which determine the correct aminoacylation process are located in the aminoacyl domain of tRNA Gly. To obtain further insight concerning structural investigation of the identity elements, the Escherichia coli seven-base-pair tRNA Gly acceptor-stem helix was crystallized. Data were collected to 2.0 Å resolution using synchrotron radiation. Crystals belong to space group P3 1 21 or P3 2 21, with unit-cell parameters a = b = 35.35, c = 130.82 Å , = = 90, = 120 and two molecules in the asymmetric unit.

Human tRNAGlyacceptor-stem microhelix: crystallization and preliminary X-ray diffraction analysis at 1.2 Å resolution

“…Here, we report the crystallization of the human tRNA Gly acceptorstem microhelix and its preliminary X-ray diffraction analysis at atomic resolution. This study contributes to the understanding of the structural elements governing the tRNA identity in general (Mueller, Muller et al, 1999;Mueller, Schü bel et al, 1999;Ramos & Varani, 1997;Seetharaman et al, 2003, Fö rster et al, 1999 and to the comparative structural analysis of the tRNA Gly system in particular (Fö rster et al, 2007).…”

“…A detailed analysis of this special system should therefore be particularly instructive in order to understand the underlying structure-function relationship and evolutionary aspects. In the present work, we focus on the human tRNA Gly system in order to complement our recent study on the corresponding Escherichia coli system (Fö rster et al, 2007); in combination, these two studies cover both types of GlyRS system.…”

Crystallization and preliminary X-ray diffraction data of an LNA 7-mer duplex derived from a ricin aptamer

“…From our data set, we calculated a Matthews coefficient of 3.17 Å 3 Da À1 with one LNA helix per asymmetric unit (Matthews, 1968). The solvent content of 70.2% seems high, but we have often observed solvent contents of approximately 65-66% for RNA crystals (Fö rster, Brauer et al, 2007;Fö rster, Perbandt et al, 2007). We can exclude the presence of a second LNA helix in the asymmetric unit as this would imply a Matthews coefficient of 1.58 Å 3 Da À1 and a solvent content of 40.1%.…”