title: Crystallization, X-ray diffraction analysis and preliminary structure determination of the TIR domain from the flax resistance protein L6.
abstract: The Toll/interleukin-1 receptor (TIR) domain is a protein-protein interaction domain that is found in both animal and plant immune receptors. In animal Toll-like receptor signalling, both homotypic TIR-domain interactions between two receptor molecules and heterotypic interactions between receptors and TIR-domain-containing adaptors are required for initiation of an innate immune response. The TIR domains in cytoplasmic nucleotide-binding/leucine-rich repeat (NB-LRR) plant disease-resistance proteins are not as well characterized, but recent studies have suggested a role in defence signalling. In this study, the crystallization, X-ray diffraction analysis and preliminary structure determination of the TIR domain from the flax resistance protein L6 (L6TIR) are reported. Plate-like crystals of L6TIR were obtained using PEG 200 as a precipitant and diffracted X-rays to 2.3 Å resolution. Pseudo-translation complicated the initial assignment of the crystal symmetry, which was ultimately found to correspond to space group P2(1)2(1)2 with two molecules per asymmetric unit. The structure of L6TIR was solved by molecular replacement using the structure of the TIR-domain-containing protein AT1G72930 from Arabidopsis as a template.
authors.affiliation: School of Chemistry and Molecular Biosciences, Institute for Molecular Bioscience (Division of Chemistry and Structural Biology), University of Queensland, Brisbane, QLD, Australia. t.ve@uq.edu.au
authors.forename: Thomas
authors.initials: T
authors.lastname: Ve
authors.forename: Simon
authors.initials: S
authors.lastname: Williams
authors.forename: Eugene
authors.initials: E
authors.lastname: Valkov
authors.forename: Jeffrey G
authors.initials: JG
authors.lastname: Ellis
authors.forename: Peter N
authors.initials: PN
authors.lastname: Dodds
authors.forename: Bostjan
authors.initials: B
authors.lastname: Kobe
mesh_terms: D020816:Amino Acid Motifs / Q000235:genetics; D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism; D002021:Buffers; D003460:Crystallization; D018360:Crystallography, X-Ray / Q000379:methods; D004926:Escherichia coli / Q000235:genetics; D019597:Flax / Q000235:genetics*; D006531:HEPES / Q000737:chemistry; D006639:Histidine / Q000737:chemistry; D006358:Hot Temperature; D006863:Hydrogen-Ion Concentration; D010935:Plant Diseases / Q000235:genetics; D010940:Plant Proteins / Q000737:chemistry* / Q000235:genetics; D017434:Protein Structure, Tertiary / Q000235:genetics; D020539:Sequence Analysis, Protein; D012995:Solubility; D013010:Sonication; D017356:Synchrotrons; D051193:Toll-Like Receptors / Q000235:genetics / Q000378:metabolism; D014169:Transformation, Bacterial
chemical_list: D002021:Buffers; C095731:L6 protein, Linum usitatissimum; D010940:Plant Proteins; D051193:Toll-Like Receptors; D006639:Histidine; D006531:HEPES