Bacteria chemical communication (Introduction)

by David Turell , Saturday, June 02, 2018, 15:24 (2364 days ago) @ David Turell

New studies show how bacteria chemically communicate and have quorum sensing. It is highly complex as all biochemical life is:

https://phys.org/news/2018-06-link-bacteria-metabolism-pave-drugs.html

"Antivirulence and antibiofilm drugs, on the other hand, block toxic molecules produced by bacteria or prevent bacteria from forming thin, slimy films called biofilms (a common example is dental plaque). These mechanisms are controlled by quorum sensing: the process that allows bacteria populations to communicate and coordinate group behavior.

***

"Quorum sensing is facilitated by signaling molecules called autoinducers. One particular autoinducer, AI-2, is modified by a protein called LsrK so that its signal can be perceived.

"The findings, which were published in the journal Science Advances, shows that LsrK forms a complex with HPr, a protein involved in glucose utilization in E. coli.

"'The fact that they are physically connected provides tantalizing evidence that these two very important pathways actually communicate," said Herman Sintim, a professor of chemistry and researcher in Purdue University's Institute for Drug Discovery.

"The research team, which included scientists from Korea Basic Science Institute and the Universty of Maryland, made another surprising discovery: whether LsrK binds to HPr depends on whether there is a phosphate group attached to HPr, which is determined by glucose availability. When glucose is present, the phosphate group on HPr is transferred to the imported sugar, but when glucose levels are low, the phosphate group on HPr is not transferred. Thus, the form of HPr with a phosphate group accumulates.

"'We've linked the absence of glucose or related sugars to the shutting down of the quorum sensing process," said Sintim. "When glucose is low, HPr, which now has a phosphate group, binds LsrK less. The uninhibited LsrK can modify AI-2, which facilitates quorum sensing. This means cooperation between E. coli and related bacteria could depend on the availability of glucose.'"

Comment: Again molecules carrying information as they interact. If the word description is confusing look at the diagram on the website. Evolution did not produce this system of communication by chance mutations.