4cqn

Crystal structure of the E.coli LeuRS-tRNA complex with the non- cognate isoleucyl adenylate analogue

spinqualitylabelsall models 4cqn, resolution 2.50Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 4cqn is a 4 chain structure with sequence from Escherichia coli and Escherichia coli K-12. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 2.5Å Ligands: ILA, MG, ZN Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function SYL_ECOLI Publication Abstract from PubMed The fidelity of protein synthesis depends on the capacity of aminoacyl-tRNA synthetases (AARSs) to couple only cognate amino acid-tRNA pairs. If amino acid selectivity is compromised, fidelity can be ensured by an inherent AARS editing activity that hydrolyses mischarged tRNAs. Here, we show that the editing activity of Escherichia coli leucyl-tRNA synthetase (EcLeuRS) is not required to prevent incorrect isoleucine incorporation. Rather, as shown by kinetic, structural and in vivo approaches, the prime biological function of LeuRS editing is to prevent mis-incorporation of the non-standard amino acid norvaline. This conclusion follows from a reassessment of the discriminatory power of LeuRS against isoleucine and the demonstration that a LeuRS editing-deficient E. coli strain grows normally in high concentrations of isoleucine but not under oxygen deprivation conditions when norvaline accumulates to substantial levels. Thus, AARS-based translational quality control is a key feature for bacterial adaptive response to oxygen deprivation. The non-essential role for editing under normal bacterial growth has important implications for the development of resistance to antimicrobial agents targeting the LeuRS editing site. The physiological target for LeuRS translational quality control is norvaline.,Cvetesic N, Palencia A, Halasz I, Cusack S, Gruic-Sovulj I EMBO J. 2014 Jun 16. pii: e201488199. PMID:24935946 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Aminoacyl tRNA synthetase 3D structures Transfer RNA (tRNA)

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