Extended Data Fig. 1: AG balancing in purine nucleotide synthesis.
From: Alternative Z-genome biosynthesis pathway shows evolutionary progression from Archaea to phage
a, Synthesis of AMP and GMP from IMP. b, PurZ and PurB are used in the extended G branch pathway to make dZMP. c, Proposed molecular evolution route from PurA to PurZ. The energy donors (ATP or GTP) are labeled in red to highlight their importance in regulating AG balance.
