|Project Theme||Structural biology of bacterial super-biosystem for import and degradation of polysaccharides and its application to food and environmental areas|
|Project Theme (short)||Polysaccharide import & degradation proteins|
|Principal Investigator||Wataru Hashimoto|
|Affiliation||Graduate School of Agriculture, Kyoto University|
|Backgrounds||- Biofilms are an aggregates of microorganisms in which cells adhere to each other and/or to a surface and are resistant to sterilization and rinsing
- One of the main components of biofilms is polysaccharides
- Some pit-forming bacteria such as Sphingomonas species A1 possess superchannels that directly incorporate and decompose polysaccharides
|Highlights||- Detailed structures and functions of cell-surface receptors at the entrance of the superchannel have been elucidated
- We have obtained the crystals of ABC importer complexes
- Structures and functions of a variety of alginate lyases have been determined
|Outline|| A biofilm is an aggregate of microorganisms in which cells adhere to each other and/or to a surface. Slime of water pipes and dental plaque are examples of biofilms. One of the main components of biofilms is polysaccharides. We have focused our study on Sphingomonas species A1, since it is a pit-forming bacterium that directly incorporates a polysaccharide (alginate) into its cytoplasm through a transport system, which we termed a superchannel. The pit functions as a concentrator of alginate, and the polymer targeted there is transported into the periplasm. The alginate introduced into the periplasm is captured by periplasmic alginate-binding proteins, transferred to an ATP-binding cassette (ABC) transporter (importer) in the inner membrane, and then transported into the cytoplasm, where it is depolymerized into its constituent monosaccharides through reactions catalyzed by alginate lyases.
We will extend our structural and functional studies on constituent proteins of this superchannel.
Biosci. Biotechnol. Biochem.