#Carter triplety code

That controversy prompted Professor Carter’s group to develop new biochemical, bioinformatic, and phylogenetic approaches to test the critical Rodin-Ohno hypothesis that the two unique synthetase classes had evolved from ancestors that, while present on the same gene, were located on opposite sense and antisense strands. The existence of bidirectional coding in this way has previously been considered controversial. The Rodin-Ohno hypothesis offered a rationale by suggesting that as DNA has two strands, perhaps each of the two strands acts as an individual coding strand, rather than one coding strand and one template (for copying) strand. Making Sense (or Antisense) of Bidirectional CodingĪ major surprise came with the discovery in 1990 that there are two distinct and apparently unrelated superfamilies of aaRS. Each amino acid is associated with one or more cognate pairs made up of one aaRS and tRNAs, whose recognition properties allow the synthetase enzyme to activate and attach the correct amino acid to one end of its cognate tRNA. These cognate pairs recognise each other very specifically and together, form the molecular dictionary. Enzymes called aminoacyl-tRNA sythetases (aaRS) recognise tRNA, forming cognate pairs.

This is facilitated by an adaptor molecule called transfer RNA (tRNA). First, we need to consider the process by which triplet codons consisting of the four bases are turned into the twenty amino acids that make up all possible proteins. Two distinct kinds of information have been embedded in nucleic acids for as long as they have served as genes. These are the mysteries that Professor Charles Carter and his team at the Department of Biochemistry and Biophysics at the University of North Carolina at Chapel Hill, USA, aim to solve.

#Carter triplety code

However, exactly how the genetic code itself first arose and how information is stored and recovered remain unclear. Translation ultimately produces a unique, coded sequence of amino acids that can fold into 3D structures called proteins. This translation process depends on a code to assign one of the 20 amino acids to each triplet of bases (codons). Once transcribed, the RNA blueprint must be interpreted so that amino acids can be correctly strung together. In order to access the information hidden in genes, the nucleotide sequence must be read and transcribed into a new version of the blueprint – messenger RNA, or mRNA.

Genes are blueprints for making proteins. Due to their work, we now know that the four nucleotide bases, the building blocks of DNA, always line up in a characteristic manner along the double helix backbone and that adenine and thymine always bind to each other, as do guanine and cytosine, ensuring that genes are passed correctly from one generation to the next. One of the biggest evolutionary questions is ‘how did we come to exist in the forms that we do?’ The most significant contribution towards answering this question was the famous discovery of the DNA double helix by Watson and Crick in 1952. Much of this work centres around the structural origins of genetics and ultimately, how chemistry created biology. His research is dedicated to investigating how information flows from genes to proteins found in living organisms via genetic coding. The research of Professor Charles Carter, University of North Carolina at Chapel Hill, USA, unravels some of the biggest mysteries of molecular evolution.