@article {328,
	title = {NMR Structure of the C-terminal domain of a tyrosyl-tRNA synthetase that functions in group I intron splicing.},
	journal = {Biochemistry},
	volume = {50},
	number = {18},
	year = {2011},
	month = {2011 May 10},
	pages = {3816-26},
	abstract = {The mitochondrial tyrosyl-tRNA synthetases (mt TyrRSs) of Pezizomycotina fungi are bifunctional proteins that aminoacylate mitochondrial tRNA(Tyr) and are structure-stabilizing splicing cofactors for group I introns. Studies with the Neurospora crassa synthetase (CYT-18 protein) showed that splicing activity is dependent upon Pezizomycotina-specific structural adaptations that form a distinct group I intron-binding site in the N-terminal catalytic domain. Although CYT-18{\textquoteright}s C-terminal domain also binds group I introns, it has been intractable to X-ray crystallography in the full-length protein. Here, we determined an NMR structure of the isolated C-terminal domain of the Aspergillus nidulans mt TyrRS, which is closely related to but smaller than CYT-18{\textquoteright}s. The structure shows an S4 fold like that of bacterial TyrRSs, but with novel features, including three Pezizomycontia-specific insertions. (15)N-(1)H two-dimensional NMR showed that C-terminal domains of the full-length A. nidulans and Geobacillus stearothermophilus synthetases do not tumble independently in solution, suggesting restricted orientations. Modeling onto a CYT-18/group I intron cocrystal structure indicates that the C-terminal domains of both subunits of the homodimeric protein bind different ends of the intron RNA, with one C-terminal domain having to undergo a large shift on its flexible linker to bind tRNA(Tyr) or the intron RNA on either side of the catalytic domain. The modeling suggests that the C-terminal domain acts together with the N-terminal domain to clamp parts of the intron{\textquoteright}s catalytic core, that at least one C-terminal domain insertion functions in group I intron binding, and that some C-terminal domain regions bind both tRNA(Tyr) and group I intron RNAs.},
	keywords = {Alternative Splicing, Aspergillus nidulans, Catalytic Domain, Crystallography, X-Ray, DNA, Geobacillus stearothermophilus, Introns, Magnetic Resonance Spectroscopy, Models, Molecular, Models, Theoretical, Molecular Conformation, Protein Structure, Secondary, Protein Structure, Tertiary, Solvents, Tyrosine-tRNA Ligase},
	issn = {1520-4995},
	doi = {10.1021/bi200189u},
	author = {Paukstelis, Paul J and Chari, Nandini and Lambowitz, Alan M and Hoffman, David}
}
