@misc{oai:repo.qst.go.jp:00074699,
 author = {西久保, 開 and 長谷川, 真保 and Yudai, Izumi(HiSOR) and 藤井, 健太郎 and Koichi, Matsuo(Tokyo-institute of Technology ) and 松本, 義久 and 横谷, 明徳 and Nishikubo, Kai and Hasegawa, Maho and Fujii, Kentaro and Matsumoto, Yoshihisa and Yokoya, Akinari},
 month = {Mar},
 note = {XRCC4 is activated via phosphorylation of its several sites by DNA-PK in the DNA double strand break repair pathway (NHEJ) (1). The phosphorylation might cause a change of static electric charge at the amino acid residues, resulting conformational alteration of the whole protein structure to permit the protein accessibility to the strand break terminus through the charge re-distribution in the protein. In order to understand the role of XRCC4 properly, it would be necessary to understand the mutual relationship between its structural change and activity change. So far, the crystallography of XRCC4 has been performed, but there is no data on the full-length of XRCC4 because it is difficult to crystallize 130 amino acid residues in the C-terminal which including several targets of phosphorylation. Instead of crystallography, we have applied circular dichroism (CD) spectral analysis for XRCC4 in an aqueous solution in a vacuum UV region at HiSOR. When compared the content of the secondary structures obtained by the CD measurement of the intact XRCC4 (denoted as WT) with that reported in the previous crystallography, the non-crystalized C-terminal region was revealed to contain significant turn structures, but not to contain β-strand. A mutated XRCC4, in which the serine-320 was substituted to an aspartic acid (denoted as S320D) to mimic phosphorylation, was also analyzed. The content of β-strand of S320D was slightly less than that of WT. The evidences indicate that β-strand in the N-terminal region was affected despite the substitution with aspartic acid induced at the C-terminal region. The phosphorylation of C-terminal region would play a role to regulate the activity of the protein through altering its whole structure, including the active center in the N-terminal., The 23rd Hiroshima International Symposium on Synchrotron Radiation},
 title = {Structural change of DNA repair protein XRCC4 by phosphorylation at c-terminal revealed by VUV-CD},
 year = {2019}
}