2j5c: Difference between revisions

Terpene synthases are responsible for the biosynthesis of the complex, chemical defense arsenal of plants and microorganisms. How do these, enzymes, which all appear to share a common terpene synthase fold, specify, the many different products made almost entirely from one of only three, substrates? Elucidation of the structure of 1,8-cineole synthase from, Salvia fruticosa (Sf-CinS1) combined with analysis of functional and, phylogenetic relationships of enzymes within Salvia species identified, active-site residues responsible for product specificity. Thus, Sf-CinS1, was successfully converted to a sabinene synthase with a minimum number of, rationally predicted substitutions, while identification of the Asn side, chain essential for water activation introduced 1,8-cineole and, alpha-terpineol activity to Salvia pomifera sabinene synthase. A major, contribution to product specificity in Sf-CinS1 appears to come from a, local deformation within one of the helices forming the active site. This, deformation is observed in all other mono- or sesquiterpene structures, available, pointing to a conserved mechanism. Moreover, a single amino, acid substitution enlarged the active-site cavity enough to accommodate, the larger farnesyl pyrophosphate substrate and led to the efficient, synthesis of sesquiterpenes, while alternate single substitutions of this, critical amino acid yielded five additional terpene synthases.

2J5C is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Salvia_fruticosa Salvia fruticosa] with BME as [http://en.wikipedia.org/wiki/ligand ligand]. Structure known Active Site: AC1. Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=2J5C OCA].  

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