Are they found in humans? I'm wondering because they display a structural similarity to glucose-6-phosphatase, which is an important enzyme in gluconeogenesis.
It is only found in an ascomycetes which is named Leptoxyphium fumago, also known as Caldariomyces fumago.
It isn't found in any other specie that we know of yet as searched on the RCSB PDB and Uni-Prot.
In researches that uses it they extract it from the organism, it is also available to buy from companies like Sigma Aldrich who extract it from the ascomycete too.