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New type of photosynthesis discovered + Microbe breaks 'universal' DNA rule by using - C C - Jun 18, 2018
New type of photosynthesis discovered
https://www.sciencedaily.com/releases/2018/06/180614213608.htm
EXCERPT: The discovery changes our understanding of the basic mechanism of photosynthesis and should rewrite the textbooks. It will also tailor the way we hunt for alien life and provide insights into how we could engineer more efficient crops that take advantage of longer wavelengths of light. [...] The vast majority of life on Earth uses visible red light in the process of photosynthesis, but the new type uses near-infrared light instead. It was detected in a wide range of cyanobacteria (blue-green algae) when they grow in near-infrared light, found in shaded conditions like bacterial mats in Yellowstone and in beach rock in Australia.
MORE: https://www.sciencedaily.com/releases/2018/06/180614213608.htm
Microbe breaks 'universal' DNA rule by using two different translations
https://www.sciencedaily.com/releases/2018/06/180614213814.htm
EXCERPT: . . . All organisms receive genetic information from their parents which tell the cells how to make proteins -- the molecules that do the chemistry in our bodies. This genetic information comprises DNA molecules made up of a sequence of four chemical bases represented by the letters A, T, C and G; the genetic code dictates to the cell which sequence of amino acids to join together to form each protein given the underlying sequence in the DNA.
In a similar way that "dot dot dot" in morse code translates as S, so too the genetic code is read in blocks of three bases (codons) to translate to one amino acid.
It was originally thought that any given codon always results in the same amino acid -- just as dot dot dot always means S in morse code. GGA in the DNA for example translates as the amino acid glycine.
However a collaboration between Dr Stefanie Mühlhausen and Professor Laurence Hurst at the Milner Centre for Evolution at the University of Bath, and Martin Kollmar and colleagues at the Max-Planck Institute for Biophysical Chemistry in Göttingen, Germany have now described the first -- and unexpected -- exception to this rule in a natural code.
The group examined an unusual group of yeasts in which some species have evolved an unusual non-universal code. While humans (and just about everything else) translate the codon CTG as the amino acid leucine, some of the species of yeast instead translate this as the amino acid serine whilst others translate it as alanine.
This is odd enough in itself. But the team was even more surprised to find one species, Ascoidea asiatica, randomly translated this codon as serine or leucine. Every time this codon is translated the cell tosses a chemical coin: heads for leucine, tails it's serine.
Laurence Hurst, Professor of Evolutionary Genetics and Director of the Milner Centre for Evolution at the University of Bath, said: "This is the first time we've seen this in any species.
"We were surprised to find that about 50 per cent of the time that CTG is translated as serine, the remainder of the time it is leucine.
"The last rule of genetics codes, that translation is deterministic, has been broken. This makes this genome unique -- you cannot work out the proteins if you know the DNA."
MORE: https://www.sciencedaily.com/releases/2018/06/180614213814.htm