Universally conserved proteins
These proteins are present in all genomes sequenced so far, from archaea and bacteria to man. So, one can say, that there is no life on earth without this small set of proteins. The genes encoding these proteins are usually essential.
- Prs phosphoribosyl-PP-synthetase
- Apt adenine phosphoribosyltransferase
- TruA pseudouridylate synthase
Aminoacyl tRNA synthetases
Degradation of glycoproteins
- Gcp sialo-glycoprotein endopeptidase