Monthly Archives:: August 2012

Mystery of operon evolution probed

Posted by & filed under Biology, News.

New research suggests a possible explanation for the organization of operons, jointly controlled clusters of genes that evolved in bacterial chromosomes. Operons, which are found in the chromosomes of bacteria but not in more advanced organisms, have puzzled biologists since their discovery in the 1960s. The new study suggests operons evolved as a means of reducing "noise" in biochemical signal processing.

Biophysicists unravel secrets of genetic switch

Posted by & filed under Biology, News.

Biophysicists have experimentally demonstrated, for the first time, how the nonspecific binding of a protein known as the lambda repressor, or C1 protein, bends DNA and helps it close a loop that switches off virulence. Findings are the first direct and quantitative determination of non-specific binding and compaction of DNA, relevant for the understanding of DNA physiology, and the dynamic characteristics of an on-off switch for the expression of genes.

‘Promiscuous’ enzymes still prevalent in metabolism: Challenges fundamental notion of enzyme specificity and efficiency

Posted by & filed under Biology, News.

Open an undergraduate biochemistry textbook and you will learn that enzymes are highly efficient and specific in catalyzing chemical reactions in living organisms, and that they evolved to this state from their “sloppy” and “promiscuous” ancestors to allow cells to grow more efficiently. This fundamental paradigm is being challenged in a new study by bioengineers who reported in the journal Science what a few enzymologists have suspected for years: many enzymes are still pretty sloppy and promiscuous, catalyzing multiple chemical reactions in living cells, for reasons that were previously not well understood.

Moving toward regeneration

Posted by & filed under Biology, News.

Scientists have shown how pluripotent stem cells mobilize in wounded planarian worms, to better understand stem cell behavior in regeneration and disease.

‘Promiscuous’ enzymes still prevalent in metabolism

Posted by & filed under Chemistry.

Open an undergraduate biochemistry textbook and you will learn that enzymes are highly efficient and specific in catalyzing chemical reactions in living organisms, and that they evolved to this state from their "sloppy" and "promiscuous" ancestors to allow cells to grow more efficiently. This fundamental paradigm is being challenged in a new study by bioengineers at the University of California, San Diego, who reported in the journal Science what a few enzymologists have suspected for years: many enzymes are still pretty sloppy and promiscuous, catalyzing multiple chemical reactions in living cells, for reasons that were previously not well understood.

Monogamy and the immune system: Differences in sexual behavior impact bacteria hosted and genes that control immunity

Posted by & filed under Health Sciences.

Researchers examined the differences between two species of mice -- one monogamous and one promiscuous -- on a microscopic and molecular level. They discovered that the lifestyles of the two mice had a direct impact on the bacterial communities that reside within the female reproductive tract. These differences correlate with enhanced diversifying selection on genes related to immunity against bacterial diseases.

Cancer gene family member functions key to cell adhesion and migration

Posted by & filed under Health Sciences.

Scientists have used sophisticated technologies to identify and describe the protein interactions that distinguish each member of the WTX family. They found that unlike WTX and FAM123C, FAM123A interacts with a specific set of proteins that regulates cell adhesion and migration, processes essential to normal cell functioning and which, when mutated, contribute to human diseases such as cancer or Alzheimer's.
Feedback

eSTEM Feedback

We appreciate any and all feedback about our site; praise, ideas, bug reports you name it!