Navigation Links
Biochemists reveal details of mysterious bacterial microcompartments
Date:2/21/2008

UCLA biochemists and colleagues have answered an important question about the structure of microcompartments the mysterious molecular machines that seem to be present in a wide variety of pathogens and other bacteria.

In the Feb. 22 issue of the journal Science, the biochemists report how the microcompartment structure closes in three dimensions, forming a shell around the enzymes encased inside.

If scientists could prevent or disrupt the formation of these microcompartments, they could probably render the bacteria harmless, said research co-author Todd O. Yeates, UCLA professor of chemistry and biochemistry and a member of the UCLADepartment of Energy Institute of Genomics and Proteomics. They do not yet know how to do this, but the current research may provide a framework for targeting microcompartments.

Yeates and his colleagues have identified the proteins that play the critical role in how the structure folds in the carboxysome, a protein shell that is the best-known and most-studied microcompartment. The shell has a structure like a soccer ball or the large, iconic dome structure at the Walt Disney World's Epcot Center.

"A soccer ball has hexagons and 12 pentagons at the corners; the pentagons are essential to close the structure," said Yeates, who is also a member of the California NanoSystems Institute at UCLA and UCLA's Molecular Biology Institute. "The Epcot Center at Walt Disney World has Spaceship Earth, a well-known dome structure composed of triangles that fit into hexagons, but on closer inspection you will find 12 locations where only five triangles come together; the same is true of the Buckminster Fuller-type domes in the desert and many viral structures.

"This principle of closing a structure by combining a large number of hexagons with a small number of pentagons to create a piece of curvature has been understood by architects, molecular biologists studying viruses and soccer ball manufacturers."

That principle is also understood by microcompartments, in which proteins form 12 pentagons to close the structure; fewer than 12 would not completely close it, said Yeates, who calls the proteins "pentameric carboxysome shell proteins."

The structure of the carboxysome shows a repeating pattern of six protein molecules packed closely together. The carboxysome has more than 3,000 sub-units with six edges and six vertices in a single shell, Yeates said.

In August 2005, Yeates and colleagues reported in the journal Science an underlying principle that governs the assembly of microcompartments: The proteins that form the outer shell form hexagons, which fit together to form extended two-dimensional molecular sheets. The researchers hypothesized that the molecular sheets formed by these hexagons formed the outer shell of the microcompartment and the tiny holes allowed small molecules to move in and out. Yeates and his colleagues have now answered how the shell closes in three dimensions.

Yeates is now studying other microcompartments that are of biomedical importance. Bacteria produce microcompartments when they infect a host, he said.

"We're learning about the kinds of strategies that bacteria have evolved to optimize the efficiency with which they operate or to deal with challenges they face," Yeates said. "In some cases, microcompartments are believed to serve a protective function, protecting the cell."

In the future, Yeates wants to learn how the shell comes to surround the enzymes, how microcompartments are formed and how microcompartments differ from one another. He is also interested in whether it is possible to create "designer microcompartments" that would encase other enzymes.

A key distinction separating the cells of primitive organisms like bacteria, known as prokaryotes, from the cells of complex organisms like humans is that complex, or eukaryotic, cells have a much higher level of sub-cellular organization.

Yeates' research blurs the distinction between eukaryotic cells and those of prokaryotes by showing that bacterial cells are more complex than scientists had imagined.

If microcompartments can be engineered, biotechnology applications could potentially arise from this research, Yeates said.


'/>"/>

Contact: Stuart Wolpert
swolpert@support.ucla.edu
310-206-0511
University of California - Los Angeles
Source:Eurekalert

Related biology news :

1. Genetic tags reveal secrets of memories staying power in mice
2. New research reveals shark superhighways and hotspots
3. Scientists rebuild ancient proteins to reveal primordial Earths temperature
4. Particle accelerator may reveal shape of alternate dimensions
5. Search for the on switches may reveal genetic role in development and disease
6. Genes linked with lupus are revealed, giving hope for new treatments
7. Researchers reveal HIV peptides possible pathway into the cell
8. Sea otter study reveals striking variability in diets and feeding strategies
9. Quakes under Pacific floor reveal unexpected circulatory system
10. New book reveals an evolutionary journey of the human body
11. New plant study reveals a deeply hidden layer of the transcriptome
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:2/26/2017)... , Feb. 25, 2017  Securus Technologies, ... technology solutions for public safety, investigation, corrections and ... Recidivism and Reentry. "Too often, too ... prisons and county jails are trying to tackle ... inmates and friends and family members. While significant steps ...
(Date:2/21/2017)... Ore. , Feb. 22, 2017  IBM (NYSE: ... (Avamere Health Services, Infinity Rehab, Signature Hospice, Home Health, ... will apply the power of IBM cognitive computing to ... centers. By analyzing data streaming from sensors in senior ... and environmental conditions, and obtain deeper learnings into the ...
(Date:2/14/2017)... , Feb. 14, 2017  Wake Forest Baptist ... as its new chief executive officer (CEO). Freischlag joins ... John D. McConnell , M.D., who last year ... at the Medical Center, after leading it since 2008. ... full scope of Wake Forest Baptist,s academic health system, ...
Breaking Biology News(10 mins):
(Date:3/22/2017)... 22, 2017 Regeneron Pharmaceuticals, Inc. (NASDAQ: REGN), today ... (RGC), U.K. Biobank and GSK to generate genetic sequence data ... The initiative will enable researchers to gain valuable insights to ... wide range of serious and life threatening diseases. ... Genetic evidence ...
(Date:3/22/2017)... March 22, 2017  Ascendis Pharma A/S (Nasdaq: ... TransCon technology to address significant unmet medical needs ... the full year ended December 31, 2016. ... our company as we broadened our pipeline and ... rare disease company with an initial focus on ...
(Date:3/22/2017)... 22, 2017 Good Start Genetics, a leading ... the 130 million covered lives mark through its most ... Texas . With newly signed contracts nationally ... enjoy strong payor acceptance based on the quality of ... genetic counseling, its industry-leading customer care and support and ...
(Date:3/22/2017)... 22, 2017   iSpecimen ®, the ... Doctors Pathology Service (DPS), a full-service anatomic pathology ... the United States , has joined a program ... Network (DHIN) to make human biospecimens and associated ... novel program, announced in 2015 as a collaboration between ...
Breaking Biology Technology: