Summary of Research Project Results under JSPS FY2001
"Research for the Future Program"

1.Research Institution Kyoto University
2.Research Area Life Sciences
3.Research Field Structure and Functional Control Mechanism of Biomolecules (Structural Biology and Functional Molecules)
4.Term of Project FY 1997 〜 FY 2001
5.Project Number 97L00501
6.Title of Project X-ray Crystallographic Study on Biological Molecular Interaction

7.Project Leader
Name Institution,Department Title of Position
Kunio Miki Kyoto University, Graduate School of Science Professor

8.Core Members

Names Institution,Department Title of Position
Isao Tanaka Hokkaido University, Graduate School of Science Professor
Akira Yasui Tohoku University, Institute of Development, Aging and Cancer Professor
Tooru Taga Kyoto University, Graduate School of Pharmaceutical Sciences Professor

9.Summary of Research Results

The aim of the project is to understand a variety of biological molecular interactions on the basis of the three-dimensional structures of protein molecules determined by X-ray crystallography. Biological molecular interactions include protein and protein, protein and nucleic acid and protein and small molecule (substrate, metal, cofactors etc.) interactions. We have determined the three-dimensional structures of the following proteins and protein complexes and discussed their structure-function relationship; chaperonin-60, thermosome α subunit complex, thermophilic photosynthetic reaction center and high potential iron-sulfur protein, and lipoprotein localization factors, LolA and LolB for protein and protein interactions, cyanobacterial DNA photolyase, and photolyase from a thermophilic bacterium and its complex with thymine, and a complex between DNA replication initiation protein RepE and DNA for protein and DNA interactions, and metapyrocatechase (a dioxygenase), human secretory phospholipase A2-IIA complex with a potent indolizine inhibitor, chitosanase, undecaprenyl diphosphate synthase, ribulose bisphosphate carboxylase/oxygenase from the hyperthermophilic archaeon (Rubisco), aldehyde reductase from a red yeast, a complex between calyculin A and the catalytic subunit of protein phosphatase 1, novel alkaline serine protease and α-amylase, and S100 family proteins, NRP8 and MRP14 for protein and small molecule interactions. We have extensively discussed about the reaction mechanism and molecular recognition controlled by the above protein molecules. In addition, it was found that mammalian photolyase homologues are essential for maintenance of circadian rhythms and their structural studies are now in progress. Synchrotron radiation, especially that in SPring-8 has been extensively used in this project, in which several effective techniques were developed.

10.Key Words

(1)X-ray crystallography、(2)three-dimensional structure、(3)synchrotron radiation facility
(4)protein-protein interaction、(5)protein-DNA interaction、(6)enzyme-substrate interaction
(7)DNA photolyase、(8)DNA replication initiator、(9)S100 family