Navigation Links
Lost in translation
Date:1/7/2009

The enzyme machine that translates a cell's DNA code into the proteins of life is nothing if not an editorial perfectionist.

Johns Hopkins researchers, reporting this week in Nature, have discovered a new "proofreading step" during which the suite of translational tools called the ribosome recognizes errors, just after making them, and definitively responds by hitting its version of a "delete" button.

It turns out, the Johns Hopkins researchers say, that the ribosome exerts far tighter quality control than anyone ever suspected over its precious protein products which, as workhorses of the cell, carry out the very business of life.

"What we now know is that in the event of miscoding, the ribosome cuts the bond and aborts the protein-in-progress, end of story," says Rachel Green, a Howard Hughes Medical Institute investigator and professor of molecular biology and genetics in the Johns Hopkins University School of Medicine. "There's no second chance." Previously, Green says, molecular biologists thought the ribosome tightly managed its actions only prior to the actual incorporation of the next building block by being super-selective about which chemical ingredients it allows to enter the process.

Because a protein's chemical "shape" dictates its function, mistakes in translating assembly codes can be toxic to cells, resulting in the misfolding of proteins often associated with neurodegenerative conditions. Working with bacterial ribosomes, Green and her team watched them react to lab-induced chemical errors and were surprised to see that the protein-manufacturing process didn't proceed as usual, getting past the error and continuing its "walk" along the DNA's protein-encoding genetic messages.

"We thought that once the mistake was made, it would have just gone on to make the next bond and the next," Green says. "But instead, we noticed that one mistake on the ribosomal assembly line begets another, and it's this compounding of errors that leads to the partially finished protein being tossed into the cellular trash," she adds.

To their further surprise, the ribosome lets go of error-laden proteins 10,000 times faster than it would normally release error-free proteins, a rate of destruction that Green says is "shocking" and reveals just how much of a stickler the ribosome is about high-fidelity protein synthesis.

"These are not subtle numbers," she says, noting that there's a clear biological cost for this ribosomal editing and jettisoning of errors, but a necessary expense.

"The cell is a wasteful system in that it makes something and then says, forget it, throw it out," Green concedes. "But it's evidently worth the waste to increase fidelity. There are places in life where fidelity matters."


'/>"/>

Contact: Maryalice Yakutchik
myakutc1@jhmi.edu
443-287-2251
Johns Hopkins Medical Institutions
Source:Eurekalert

Related biology news :

1. New York Stem Cell Foundation announces third annual Translational Stem Cell Research Conference
2. Study reveals surprising details of the evolution of protein translation
3. NIH expands national consortium dedicated to transforming clinical and translational research
4. Improving care and knowledge in translational research to fight breast cancer
5. Translational research patented first experimental treatment against idiopathic pulmonary fibrosis
6. Shilatifard Lab sheds light on molecular machinery required for translation of histone crosstalk
7. AACR, BCRF award inaugural grants in translational breast cancer research
8. NIH awards nearly $23M to University of Chicago for translational research
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:8/23/2017)... ARMONK, N.Y. , Aug. 23, 2017  The general public,s help ... the human microbiome—the bacteria that live in and on the human body ... ... bacteria in the human microbiome, starting with the gut. The project's goal ... in disease. Photo credit: IBM ...
(Date:6/23/2017)... ARMONK, N.Y. and ITHACA, N.Y. ... IBM ) and Cornell University, a leader in dairy ... combined with bioinformatics designed to help reduce the chances ... breaches. With the onset of this dairy project, Cornell ... the Consortium for Sequencing the Food Supply Chain, a ...
(Date:5/16/2017)... , May 16, 2017   Bridge Patient ... organizations, and MD EMR Systems , an ... partner for GE, have established a partnership to ... product and the GE Centricity™ products, including Centricity ... These new integrations will allow ...
Breaking Biology News(10 mins):
(Date:10/10/2017)... , ... October 10, 2017 , ... ... of 13 prestigious awards honoring scientists who have made outstanding ... a scheduled symposium during Pittcon 2018, the world’s leading conference and exposition for ...
(Date:10/9/2017)... ... 09, 2017 , ... The award-winning American Farmer television series will feature 3 ... airs Tuesdays at 8:30aET on RFD-TV. , With global population estimates nearing ten ... to continue to feed a growing nation. At the same time, many of our ...
(Date:10/9/2017)... Arizona (PRWEB) , ... October 09, 2017 , ... ... Kindred, a four-tiered line of medical marijuana products targeting the needs of consumers ... and packaging of Kindred takes place in Phoenix, Arizona. , As operators of ...
(Date:10/7/2017)... Arizona (PRWEB) , ... October ... ... 15 years’ experience providing advanced instruments and applications consulting for microscopy and ... in-house expertise in application consulting, Nanoscience Analytical offers a broad range of ...
Breaking Biology Technology: