This is a Paz domain found in Argonaute proteins from Aquifex aeolicus bacteria. The PAZ core fold in Aquifex aeolicus bacteria Ago (Aa-Ago) proteins is closely related to the human hAgo1 PAZ domain. Structural and functional studies of Aa-Ago indicate that conformational rearrangement of the PAZ domain may be critical for the catalytic cycle of Argonaute and the RNA-induced silencing complex.
Jiyao W et al.(2023). "The conserved domain database in 2023.",