Missing link in microbial cellulose decomposition
A University of Tokyo research group has revealed for the first time the three-dimensional structure and mechanism of action of a key enzyme of bio-fuel production, cellobionic acid phosphorylase (CBAP). This result is important basic information for developing the technology to make bio-fuel and other chemical products from biomass.
It has been long thought that hydrolytic enzymes (cellulases) were the main contributors to microbial degradation of cellulose. Recently, the existence of oxidative cellulose-degrading enzymes that dramatically increase the activity efficiency of cellulases have been noted.
When these enzymes degrade cellulose, cellobionic acid is produced. However, it was completely unknown how the cellulolytic microbes further metabolize this compound.
In 2013, one of the members of the research group, Associate Professor Hiroyuki Nakai at the Graduate School of Science and Technology, Niigata University, discovered a new enzyme, cellobionic acid phosphorylase (CBAP).
CBAP catalyzes the degradation of cellobionic acid to produce compounds that are prone to further metabolism and fermentation. Therefore, this enzyme is a missing link between the oxidative cellulose degradation and bioethanol fermentation pathways in microorganisms. However, the three dimensional structure of the enzyme and the mechanism by which it degraded cellobionic acid remained unknown.
In this latest research, the research group lead by Professor Shinya Fushinobu at the University of Tokyo, Graduate School of Agricultural and Life Sciences, used X-ray crystallography to reveal the three-dimensional structure of CBAP isolated from marine bacteria. In addition, the structure of CBAP in complex with cellobionic acid was determined (figure), and the reaction mechanism for decomposing cellobionic acid was revealed.
“This research is extremely interesting from a scientific perspective, but could also contribute to the development of biorefinery technologies that produce biofuels such as ethanol and other useful compounds via biomass degradation by microbes,” says Professor Fushinobu.
Two cellobionic acid phosphorylases molecules pair up to create a dimer. The colored left half and the gray right half are each one enzyme molecule. Cellobionic acid and sulfuric acid ions (a compound similar to phosphoric acid) bound to cellobionic acid phosphorylase are expressed as spheres in the figure.
Young-Woo Nam, Takanori Nihira, Takatoshi Arakawa, Yuka Saito, Motomitsu Kitaoka, Hiroyuki Nakai, and Shinya Fushinobu, "Crystal structure and substrate recognition of cellobionic acid phosphorylase playing a key role in oxidative cellulose degradation by microbes", The Journal of Biological Chemistry Vol. 290, No. 30, pg 18281-18292, doi: 10.1074/jbc.M115.664664.
UTokyo Research article
Euan McKay | ResearchSea
Novel mechanisms of action discovered for the skin cancer medication Imiquimod
21.10.2016 | Technische Universität München
Second research flight into zero gravity
21.10.2016 | Universität Zürich
Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.
"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...
In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.
A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...
By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.
"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...
COMPAMED has become the leading international marketplace for suppliers of medical manufacturing. The trade fair, which takes place every November and is co-located to MEDICA in Dusseldorf, has been steadily growing over the past years and shows that medical technology remains a rapidly growing market.
In 2016, the joint pavilion by the IVAM Microtechnology Network, the Product Market “High-tech for Medical Devices”, will be located in Hall 8a again and will...
'Ferroelectric' materials can switch between different states of electrical polarization in response to an external electric field. This flexibility means they show promise for many applications, for example in electronic devices and computer memory. Current ferroelectric materials are highly valued for their thermal and chemical stability and rapid electro-mechanical responses, but creating a material that is scalable down to the tiny sizes needed for technologies like silicon-based semiconductors (Si-based CMOS) has proven challenging.
Now, Hiroshi Funakubo and co-workers at the Tokyo Institute of Technology, in collaboration with researchers across Japan, have conducted experiments to...
14.10.2016 | Event News
14.10.2016 | Event News
12.10.2016 | Event News
21.10.2016 | Health and Medicine
21.10.2016 | Information Technology
21.10.2016 | Materials Sciences