The Journal of Biological Chemistry has ranked this documentation as “Paper of the Week.”
A virus that infects the marine cyanobacterium Prochlorococcus can produce specific pigments more effectively than its host can. It requires only one enzyme, in contrast to the host Prochlorococcus, which needs two enzymes. The virus makes use of phycoerythrobilin synthase, a “two in one” enzyme.
Within the frameworks of his dissertation, Thorben Dammeyer, a member of the research team under the supervision of Prof. Nicole Frankenberg-Dinkel (Physiology of Microorganisms) and Assistant Professor Dr. Eckhard Hofmann (X-ray diffraction analysis of proteins), solved the 3D structure of the enzyme. An unexpected flexibility was discovered, allowing sections of the protein to assume different positions – an unusual property for proteins in combination with their substrate. The scientists have documented their results, honored as “Paper of the Week,” in the current issue of the Journal of Biological Chemistry.
Pigments are produced in two steps
The so-called P-SSM2 virus with the “two in one” enzyme infects the cyanobacterium Prochlorococcus, a cyanobacterium found in extremely large numbers in the worlds oceans. The virus does however differ in that - in contrast to its cyanobacterial relatives - it does not harvest light for photosynthesis via red and blue pigments, but with chlorophyll, as is the case with higher plants. Nevertheless Prochlorococcus contains all the genetic information for the entire machinery required to produce these pigments. This takes place in two steps with two different enzymes as catalysts.
Green turns red in one step
Nicole Frankenberg-Dinkel stated that “we have discovered the genetic blueprint for an enzyme within the virus. This enzyme is capable of producing the red pigment more effectively than its host, which has convinced us that the pigment cannot be unimportant for Prochlorococcus, even if it is not required for light trapping. On the other hand, we obviously wanted to know how this enzyme can combine two functions.” The scientists used X-ray diffraction analysis to determine the 3D structure of the enzyme at atomic resolution both alone and in complex with its natural substrate, the green biliverdin IXa. This molecule was found in the binding pocket of the protein, where the conversion into a red pigment takes place. Prof. Frankenberg-Dinkel explained that the scientists were able to observe how different parts of the enzyme around the binding pocket are capable of assuming different positions. “This property might not be unusual for proteins in solution, but is extremely rarely found in protein crystals.” The structural variations observed supplied the scientists with the first indications of the movements of the enzyme during catalysis.
Next step: tracking the evolution
The next stage of research will consist of studies of targeted and randomly genetically altered forms of the unusually flexible protein. Using this system, the scientists want to observe the in vitro evolution of this specific enzyme. Nicole Frankenberg-Dinkel’s and Eckhard Hofmann’s research teams are funded by the Collaborative Research Centre 480 “Molecular Biology of Complex Functions in Botanical Systems.”
Prof. Dr. Frankenberg-Dinkel | alfa
First time-lapse footage of cell activity during limb regeneration
25.10.2016 | eLife
Phenotype at the push of a button
25.10.2016 | Institut für Pflanzenbiochemie
Ultrafast lasers have introduced new possibilities in engraving ultrafine structures, and scientists are now also investigating how to use them to etch microstructures into thin glass. There are possible applications in analytics (lab on a chip) and especially in electronics and the consumer sector, where great interest has been shown.
This new method was born of a surprising phenomenon: irradiating glass in a particular way with an ultrafast laser has the effect of making the glass up to a...
Terahertz excitation of selected crystal vibrations leads to an effective magnetic field that drives coherent spin motion
Controlling functional properties by light is one of the grand goals in modern condensed matter physics and materials science. A new study now demonstrates how...
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...
14.10.2016 | Event News
14.10.2016 | Event News
12.10.2016 | Event News
25.10.2016 | Earth Sciences
25.10.2016 | Power and Electrical Engineering
25.10.2016 | Process Engineering