Glutamate (neurotransmitter)
Glutamate is a major constituent of a wide variety of proteins; consequently it is one of the most abundant amino acids in the human body. Under ordinary conditions enough is obtained from the diet that there is no need for any to be synthesized. Nevertheless, glutamate is formally classified as a non-essential amino acid, because it can be synthesized from alpha-Ketoglutaric acid, which is produced as part of the citric acid cycle by a series of reactions whose starting point is citrate. Glutamate cannot cross the blood-brain barrier unassisted, but it is actively transported into the nervous system by a high affinity transport system, which maintains its concentration in brain fluids at a fairly constant level.
FAM63A
In FAM63A, there are several amino acids that are conserved in all vertebrates for which sequences are available. Gly239 is the only amino acid that is conserved in all vertebrates, invertebrates, and plants for which sequences are available. Because there is only one amino acid that is absolutely conserved, a possible function for the conserved Glycine was not deduced. The 25 amino acid sequence ranging from Val313 to Gly338 is the most highly conserved in all vertebrates, invertebrates, and plants for which sequences are available. Although the sequence is not absolutely conserved, it is very highly conserved, even in the most distantly related organisms like fungi and plants.