Laboratory of Supermolecular Crystallography
Institute for Protein ResearchProfessor

Atsushi NAKAGAWA

atsushi

Associate Professor

Eiki YAMASHITA

eiki

URL: http://www.protein.osaka-u.ac.jp/rcsfp/supracryst/
There are various biologicalmacromolecular assemblies
consisting of proteins, nucleic
acids, sugars, lipids, and othersubstances in living cells. Thesemacromolecular assemblies play
key roles in all living systems. Ourlaboratory works on structure
determination of biologicalmacromolecular assemblies, as wellas proteins, which play importantroles in biological systems, using Xray crystallography and cryoelectron micrography.
Development of tools for X-ray
crystal structure determination of
biological macromolecularassemblies, including synchrotron
radiation beamtime at SPring-8, isalso one of our main works.
Development of a method forstructural analysis of biologicalmacromolecular complexes
Crystals of biological macromolecularcomplexes are known to have larger lattice
constants and much weaker diffraction
intensities than ordinary protein crystals.
Furthermore, many of them are easily
damaged by X-ray irradiation. In order tomeasure the diffraction intensity data fromsuch biological supramolecular complex
crystals with high resolution and accuracy,
we are operating a contract beamline,
BL44XU, at SPring-8, a large synchrotron
radiation facility. In addition, we aredeveloping new X-ray crystallographymethods, such as high-precision dataacquisition methods and automatic structurerefinement pipeline.
Structural analysis of biologicalmacromolecular assemblies
Our laboratory aims to elucidate themolecular interactions and molecularrecognition mechanisms that are importantfor understanding biological functions
based on precise atomic structures.

For this purpose, X-ray
crystallography and cryoelectron micrography areused.
Major research targets
include Rice dwarf virus
with a molecular weight of
75 million, PfV, a virus-likeparticle that forms stablespherical particles evenunder high temperature
conditions of over 90 ˚C,drug efflux complexes thatplay an important role indrug resistance inPseudomonas aeruginosa,
one of the bacteria causing
hospital-acquired infections.

Figure 1: SPring-8's Biological Macromolecular
Structure Beamlines

Structural analysis ofproteins important forbiological functions
Following the results of the Protein
3000 Project, which has been carriedout for five years since FY2002, andthe Targeted Proteins Research
Program, which has been carried out
for five years since FY2007, we aim tofurther develop these projects andconduct research aimed atunderstanding the structure andfunctions of proteins important forbiological functions through thestructural analysis of many proteins
inside and outside of the university.
We are collaborating withlaboratories. Major research targets
include novel families of membranepotential sensor proteins, intracellularsignaling protein complexes, andintercellular adhesion molecules.
Please keep in mind toacquire a broad

perspective, not limited
to your specialty.

Figure 2: Structure of theforeign body efflux protein
complex MexAB-OprM
from Pseudomonas
aeruginosa（Tsutsumi et al.,Nat. Commun., 2019）

Institute for Protein Research, Osaka University
3-2 Yamadaoka, Suita, Osaka 565-0871, Japan
TEL: +81-6-6105-8635
FAX : +81-6-6105-4313
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