GMP synthase (glutamine-hydrolyzing), C-terminal domain or B subunit
This protein of purine de novo biosynthesis is well-conserved. However, it appears to split into two separate polypeptide chains in most of the Archaea. This C-terminal region would be the larger subunit [Purines, pyrimidines, nucleosides, and nucleotides, Purine ribonucleotide biosynthesis]
Jiyao W et al.(2023). "The conserved domain database in 2023.",