1987 Fiscal Year Final Research Report Summary
Versatality of Nucleic Acid Structure and its recognition
| Project/Area Number |
61303019
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| Research Category |
Grant-in-Aid for Co-operative Research (A)
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| Allocation Type | Single-year Grants |
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| Research Field |
生物物性学
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| Research Institution | Tokyo College of Pharmacy |
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Principal Investigator |
SHINDO Heisaburo Tokyo College of Pharmacy, 薬学部, 助教授 (80138966)
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| Co-Investigator(Kenkyū-buntansha) |
KYOGOKU Yoshimasa Osaka University, Protein Institute, 蛋白質研究所, 教授 (90012632)
HAKOSHIMA Toshio Osaka University, Faculty of Phamaceutical Science, 薬学部, 助手 (00164773)
NISHIKAWA Kazuya Nagoya University,Faculty of Science, 理学部, 助手 (60109262)
YOKOYAMA Shigeyuki The University of Tokyo Faculty of Science, 理学部, 助教授 (00159229)
NISHIMURA Yoshifumi The Univesity of Tokyo,faculty of Pharmaceutical Sci., 薬学部, 助手 (70107390)
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| Project Period (FY) |
1986 – 1987
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| Keywords | Structures of DNA / Structure and function of tRNA / HU protein / cro repressor / Structure of hairpin loop / Structure of bulge loop / Dynamics of DNA / NMR / CD |
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| Research Abstract |
(i) Versatality of the Structure of OligoDNAs. Four different structures characterized by sugar prosphate conformations were demonstrated by ramann spectroscopy, and they were designated as Bn form specific to GC, Bh form to GG, Bn form to AT and B' form to AA sequences. Furthermore, cleavaga pattern of restriction enzymes were reasonably interpreted in terms of structural rigidity of diad sequences, i.e., the most rigid structural unit such as CA was hardly cleaved,whereas soft structural unit such as CT was often an attacked site by the enzymes.
(2) Hairpin and Bulge Loop Structures. Loop structures were found to be unexpectedly stablized by base stacking interactions. The stability of hairpin loop was maximum when loop length n=1-3, while the stability of bulge loop monotoneously decreased as an increasing loop length.
(3) Versatality of tRNA and its Interaction with Aminoacylase. tRNA _<minor>^<Ile> which codes Ile was sequenced, and the first letter of its anticodon was found to be new nucleotide, lysidylcytidine named as lysidine. In the gene of this tRNA the first letter of the anticodon was C but the modified cytidine in the mature tRNA recognized A. Interesting relations between higher structure of tRNA and its function were obtained by means of acceptability of amino acids by modification of anticodon bases.
(4) DNA-Protein Complexes. Single crystal structure of HU-DNA were solved at 3.5 A resolution,and interacting modes of HU-HU and unique orientation of bound oligo octamers in the crystal unit were clarified. As for cro-DNA complex the binding modes and its strength were measured by NMR and CD as a function of base sequence of base sequence of bound DNA, as the reslts concluded that only the consensus sequence for the operator induced the structural changes in both cro protein and DNA itself by complex formation.
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