Structure of macrophomate synthase.

Abstract

Macrophomate synthase (MPS) is an enzyme that catalyzes an extraordinarily complex conversion reaction, including two decarboxylations, two carbon-carbon bond formations and a dehydration, to form the benzoate analogue macrophomate from a 2-pyrone derivative and oxalacetate. Of these reactions, the two carbon-carbon bond formations are especially noteworthy because previous experiments have indicated that they proceed via a Diels-Alder reaction, one of the most widely used reactions in organic synthesis. The structural evidence that MPS catalyzes an intermolecular Diels-Alder reaction has been reported recently [Ose et al. (2003), Nature (London), 422, 185-189]. Interestingly, the tertiary structure as well as the quaternary structure of MPS are similar to those of 2-dehydro-3-deoxygalactarate (DDG) aldolase, a carbon-carbon bond-forming enzyme that catalyzes the reversible reaction of aldol condensation/cleavage. Here, the structure of MPS is described in detail and compared with that of DDG aldolase. Both enzymes have a (beta/alpha)(8)-barrel fold and are classified as belonging to the enolase superfamily based on their reaction strategy. The basic principles for carbon-carbon bond formation used by both MPS and DDG aldolase are the same with regard to trapping the enolate substrate and inducing subsequent reaction. The major differences in the active sites between these two enzymes are the recognition mechanisms of the second substrates, 2-pyrone and DDG, respectively.

• Authors: Toyoyuki Ose, Kenji Watanabe, Min Yao, Mamoru Honma, Hideaki Oikawa, Isao Tanaka
• Journal: Acta crystallographica. Section D, Biological crystallography (Acta Crystallogr D Biol Crystallogr) Vol. 60 Issue Pt 7 Pg. 1187-97 (Jul 2004) ISSN: 0907-4449 [Print] United States
• PMID: 15213379 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Multienzyme Complexes
• macrophomate synthase
• Aldehyde-Lyases
• 2-dehydro-3-deoxygalactarate aldolase

Topics

• Aldehyde-Lyases (chemistry)
• Amino Acid Sequence
• Ascomycota (enzymology)
• Binding Sites
• Crystallography, X-Ray
• Models, Molecular
• Molecular Sequence Data
• Molecular Structure
• Multienzyme Complexes (chemistry, metabolism)
• Protein Structure, Tertiary
• Sequence Alignment