Critical amino acids for the 8(R)-dioxygenase activity of linoleate diol synthase. A comparison with cyclooxygenases
2008 (English)In: FEBS Letters, ISSN 0014-5793, Vol. 582, no 23-24, 3547-51 p.Article in journal (Refereed) Published
7,8-Linoleate diol synthase (7,8-LDS) of the take-all fungus and cyclooxygenases can be aligned with approximately 24% amino acid identity and both form a tyrosyl radical during catalysis. 7,8-LDS was expressed in insect cells with native 8R-dioxygenase and hydroperoxide isomerase activities. We studied conserved residues of 7,8-LDS, which participate in cyclooxygenases for heme binding (His residues), hydrogen abstraction (Tyr), positioning (Tyr, Trp), and ionic binding of substrates (Arg). Site-directed mutagenesis abolished 8R-dioxygenase activities with exception of the putative distal histidine (His203Gln) and a tyrosine residue important for hydrogen bonding and substrate positioning (Tyr329Phe). The results demonstrate structural similarities between 7,8-LDS and cyclooxygenases.
Place, publisher, year, edition, pages
2008. Vol. 582, no 23-24, 3547-51 p.
Cyclooxygenase, 8R-Dioxygenase, 8-Hydroperoxylinoleic acid, Hydroperoxide isomerase, LC–MS, Myeloperoxidase, Gaeumannomyces graminis
IdentifiersURN: urn:nbn:se:uu:diva-102422DOI: 10.1016/j.febslet.2008.09.031ISI: 000260806700050PubMedID: 18812175OAI: oai:DiVA.org:uu-102422DiVA: diva2:216124