■ Introduction to Research〓 Research Area : Microbial Function

Frontiers of Nucleoside Antibiotics with Antifungal,Antiviral, and Antitrypanose Activities.
Nucleoside antibiotics comprise a group of microbial products, which has antifungal, antiviral and anti-protozoan activities. These antibiotics,
mostly produced by Streptomycetes species as their secondary metabolites, can inhibit parasite-specific processes such as viral proliferationand protozoan-specific metabolism. Despite the potential utility and yet increasing demands
for such powerful antibiotics, there are few successful utilization case of antiviral and anti-parasitic activity of the nucleoside antibiotics, due exclusively to the poor production yield and thedifficulty in identifying the biosynthetic genes in the genome of the producer strains. The present
research aims to develop an alternative strategy for production improvement by modifying thecellular machineries for transcription and translation to increase and maintain the biosynthetic enzymes without the need of cloning the biosyntheticgenes. RNA polymerase genes and ribosomal genes are altered on theNucleoside antibiotic producing strain
genome to increase and maintain the biosynthetic genes.
Streptomyces incarnatus NRRL8087.

Engineering RNA polymerase based on Molecular Dynamics Simulation and Density
Function Theory Calculation - QM/MM Estimation and Experimental Proof.

〓 Prof.
TAMURA Takashi

Computation of RNA polymerase
to improve the transcription rate.

RNA polymerase (RNAP) has four conserved residues, which
are collectively termed as rif-1 cluster residues, in the β-subunit.
Alteration of the rif-1 residues by site-directed mutation very
often results in production enhancement of the secondary metabolites. The residues are positioned to interact with the newly
synthesized mRNA, and they can regulate the polymerization
rate. Multiple combination of mutation can alter the interaction
between the β-subunit and RNA chain, which is also computed
by MD-modeling and Density Function Theory calculation. Computation gives the theoretical consequence of residue change
in terms of interaction energy at the electronic levels, and experimental data gives clues on the most appropriate interaction forthe highly enhanced production of the secondary metabolite .

〓 Research Area : Plant Genetics and Physiology

Photosynthesis and chloroplast biogenesis:
Understanding to innovation
Plants perform photosynthesis in chloroplasts, where light energy is converted into chemical energy by a series of electrochemical reactions. In contrast, sessile land plants are exposed
incessantly to excess light energy or harsh atmospheric environments that engender ‘photodamage’. How do plants cope withsuch photosynthetic inactivation? What are the key elements tomaintaining or even maximizing chloroplast functions?
Our group studies various aspects of chloroplast development and photosynthesis. Through understanding of the factors involved in photoprotection and chloroplast function, we aim at improving crop productivity
against atmospheric stress over the long term.

Ongoing projects in Plant Light Acclimation Research Group
1. Proteolytic machineries in chloroplasts

2. Photooxidative stress and quality control of photosynthetic proteins
3. Maintenance of chloroplast envelope through protection
mechanism through VIPP1〓 Prof.
SAKAMOTO Wataru〓 Asst. Prof.
OKEGAWA Yuki

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4. Behavior of chloroplast DNAs during leaf maturation andsenescence
5. Quantitative trait locus (QTL) controlling stay green insorghum