Fig. 2
From: Biosynthetic energy cost for amino acids decreases in cancer evolution
Biosynthetic cost of AAs constrains their usage in mammalian proteomes. a A model that explains anticorrelation between the usage of AAs in human proteomes and their cost in autotrophs (B20 or Y20) and heterotrophs (H11). Free AA pool in human cells comes from two sources: (1) NEAAs that are endogenously synthesized in human or other animal cells, which are constrained by H11 cost metric; and (2) AAs ultimately taken from autotrophs, which are constrained by B20 or Y20 cost metric. As a result, the total free AAs show anticorrelation with cost in heterotrophs (H11) or cost in autotrophs (B20 or Y20). Bioavailability of free AAs further shapes AA usage in human proteomes by optimizing compositions of protein sequences and expression levels of genes during evolution. b The relationship between the biosynthetic cost of AAs (B20, Y20, H11) and experimentally measured in vivo concentration of free AAs in mammalian tissues
