This entry contains bacterial 6-phosphogluconolactonases (6PGL)YbhE-type (EC:3.1.1.31) which hydrolyse 6-phosphogluconolactone to 6-phosphogluconate. The entry also contains the fungal muconate lactonising enzyme carboxy-cis,cis-muconate cyclase (EC:5.5.1.5) and muconate cycloisomerase (EC:5.5.1.1), which convert cis,cis-muconates to muconolactones and vice versa as part of the microbial beta-ketoadipate pathway. Structures of proteins in this family have revealed a 7-bladed beta-propeller fold.