title: Recruitment of thioredoxin-like domains into prostaglandin synthases.
abstract: A variety of prostaglandin (PG) synthases with different evolutionary origins have been identified. These enzymes catalyze reduction and oxidation reactions. However, despite the similarity in their reactions, thioredoxin-like proteins were not found in the PG synthesis pathway until recently. We have identified two new enzymes, thioredoxin-type PGF synthase and membrane-associated PGE synthase-2, with thioredoxin-like domains. In addition, the N-terminal domain of hematopoietic PGD synthase is classified into the thioredoxin-like superfamily, based on structural similarity. The active sites of the former two enzymes have a CXXC motif, which is also critical for the thioredoxin activity. In contrast, hematopoietic PGD synthase lacks the motif, and the activity is carried out by glutathione. A phylogenetic tree of the thioredoxin-like domains suggests that they have been independently recruited into these PG synthases. We will discuss the functional meaning of the thioredoxin-like domains in the PG synthases from the viewpoint of the redox activity.
authors.affiliation: Center for Advanced Medical Engineering and Informatics, Osaka University, 1-3 Machikaneyama, Toyonaka, Osaka 560-8531, Japan.
authors.forename: Hiromi
authors.initials: H
authors.lastname: Daiyasu
authors.forename: Kikuko
authors.initials: K
authors.lastname: Watanabe
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Toh
mesh_terms: D020816:Amino Acid Motifs; D001665:Binding Sites; D004789:Enzyme Activation; D010084:Oxidation-Reduction; D011451:Prostaglandin-Endoperoxide Synthases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D013329:Structure-Activity Relationship; D013879:Thioredoxins / Q000737:chemistry* / Q000378:metabolism*
chemical_list: D013879:Thioredoxins; D011451:Prostaglandin-Endoperoxide Synthases