Figure 1: Overview of the dTTP biosynthesis pathways.
From: Trading in cooperativity for specificity to maintain uracil-free DNA
The three dimensional structures of the nucleotides were extracted from pdb files (dCTP: 1XS4; dUTP: 2V9X; dUMP: 1SNF; dTMP: 1TMK; dTTP: 2QXX; dCMP: 1B5E; dThd: 2V9X) and are shown as atomic colored sticks (C: grey, O: red; N: blue; P: orange). Circled chemical groups call attention to the differences relevant to the enzymatic reactions that transform pyrimidine nucleotides into each other.
