Genome complexity; another code (Introduction)

by David Turell , Monday, January 21, 2013, 14:53 (4325 days ago) @ David Turell

Varying production of amino acids under stress:-"What we found was that if the bacteria are in an environment where they can grow and thrive, each synonymous codon produces the same amount of protein," Subramaniam said. "But the moment we put them in an environment where they are starved of an amino acid, some codons produce a hundredfold more proteins than others." The difference, he said, lay with molecules called transfer RNA, or tRNA, which ferry amino acids to the cellular machinery that manufactures proteins. "What we found was that some of these tRNA molecules are much more efficient at being loaded with amino acids, while others are less so," Subramaniam said. "If these tRNA molecules can't deliver the amino acid to where it needs to be, the cell cannot manufacture the proteins it needs. In an environment where amino acids are in short supply, that ability to hold onto them becomes very important." While the system helps cells to make certain proteins efficiently under stressful conditions, it also acts as a biological failsafe, allowing the near-complete shutdown in the production of other proteins as a way to preserve limited resources.- Read more at: http://phys.org/news/2013-01-hidden-genetic-code-key-differences.html#jCp