Masaru Tsunoda

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The specific aminoacylation of tRNA by tyrosyl-tRNA synthetases (TyrRSs) relies on the identity determinants in the cognate tRNA(Tyr)s. We have determined the crystal structure of Saccharomyces cerevisiae TyrRS (SceTyrRS) complexed with a Tyr-AMP analog and the native tRNA(Tyr)(GPsiA). Structural information for TyrRS-tRNA(Tyr) complexes is now full-line(More)
Proliferating cell nuclear antigen (PCNA) is a key protein that orchestrates the arrangement of DNA-processing proteins on DNA during DNA metabolism. In crenarchaea, PCNA forms a heterotrimer (PCNA123) consisting of PCNA1, PCNA2, and PCNA3, while in most eukaryotes and many archaea PCNAs form a homotrimer. Interestingly, unique oligomeric PCNAs from(More)
The enzyme urate oxidase catalyzes the conversion of uric acid to 5-hydroxyisourate, one of the steps in the ureide pathway. Arthrobacter globiformis urate oxidase (AgUOX) was crystallized and structures of crystals soaked in the substrate uric acid, the inhibitor 8-azaxanthin and allantoin have been determined at 1.9-2.2 A resolution. The biological unit(More)
Faculty of Pharmacy, Iwaki Meisei University, 5-5-1 Chuodai-Iino, Iwaki, Fukushima 970-8551, Japan, Department of Biochemistry and Molecular Biology, Rajshahi University, Rajshahi, Bangladesh, College of Science and Engineering, Iwaki Meisei University, Iwaki, Fukushima 970-8551, Japan, Graduate School of Science and Engineering, Iwaki Meisei University,(More)
The filamentous bacteriophage Pf1, which infects strain PAK of Pseudomonas aeruginosa, is a flexible filament ( approximately 2000 x 6.5 nm) consisting of a covalently closed DNA loop of 7349 nucleotides sheathed by 7350 copies of a 46-residue alpha-helical subunit. The subunit alpha-helices, which are inclined at a small average angle ( approximately 16(More)
To investigate the mutation mechanism of purine transition in DNA damaged with methoxyamine, a DNA dodecamer with the sequence d(CGCGAATTmo(4)CGCG), where mo(4)C is 2'-deoxy-N(4)-methoxycytidine, has been synthesized and its crystal structure determined. Two dodecamers form a B-form duplex. Electron density maps clearly show that one of the two mo(4)C(More)
To investigate the mutation mechanism of purine transitions in DNA damaged with methoxyamine, a DNA dodecamer with the sequence d(CGCAAATTmo(4)CGCG), where mo(4)C is 2'-deoxy-N(4)-methoxycytidine, has been synthesized and the crystal structure determined by X-ray analysis. The duplex structure is similar to that of the original undamaged B-form dodecamer,(More)
Hydroxyl radicals are potent mutagens that attack DNA to form various base and ribose derivatives. One of the major damaged thymine derivatives is 5-formyluracil (fU), which induces pyrimidine transition during replication. In order to establish the structural basis for such mutagenesis, the crystal structures of two kinds of DNA d(CGCGRATfUCGCG) with R =(More)
Actinohivin (AH) is a microbial lectin containing 114 amino acids, which inhibits human immunodeficiency virus (HIV) infection. This effect is brought about by its specific binding to Man-α(1-2)-Man unit(s) of high-mannose type glycan (HMTG) bound to HIV gp120. The recently determined crystal structure of AH suggests that three repeated segments (the(More)
Yeast tyrosyl-tRNA synthetase (yTyrRS) has been crystallized by the vapor diffusion method in the presence of its cognate tRNA(Tyr). The crystals belong to a tetragonal space group P4(1)2(1)2 with cell dimensions of a = b = 63.85 Angstrom, and c = 330.3 Angstrom. The asymmetric unit contains one molecule each of yTyrRS and tRNA(Tyr) (one-half of a 2:2(More)