You may have noticed that CauseScience blog has a new logo! The new logo design is a representation of the chemical structure of the amino acid methionine. Methionine has the chemical structure HO2CCH(NH2)CH2CH2SCH3. It is one of just two essential amino acids that contain Sulfur. Methionine is especially important in genetics and biochemistry, because in the genetic code, it is only coded for with a single codon, AUG. AUG is also the most common start codon for protein coding genes, thus methionine is at the beginning of most proteins.
The methionine codon AUG is also the most common start codon. A “Start” codon is message for a ribosome that signals the initiation of proteintranslation from mRNA when the AUG codon is in a Kozak consensus sequence. As a consequence, methionine is often incorporated into the N-terminal position of proteins in eukaryotes and archaea during translation, although it can be removed by post-translational modification. In bacteria, the derivative N-formylmethionine is used as the initial amino acid.
CauseScience picked methionine for a number of reasons. First, it is a common and important amino acid that contains a carbon and sulfur (so we could incorporate the C and S of CauseScience). Second, it is a relatively simple structure to draw out… my chemistry knowledge only extends a little beyond Chemistry 101 and Organic Chemistry. Lastly, like methionine, we hope that CauseScience Blog is the beginning of something bigger. Maybe for science outreach, science advocacy, science news, science explanation, or just fun science for us to write about!