Biochemical Investigations of Two 6‐DMATS Enzymes from Streptomyces Reveal New Features of L‐Tryptophan Prenyltransferases |
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| Authors: | Julia Winkelblech Prof. Dr. Shu‐Ming Li |
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| Affiliation: | 1. Philipps‐Universit?t Marburg, Institut für Pharmazeutische Biologie und Biotechnologie, Deutschhausstrasse 17A, 35037 Marburg (Germany);2. Zentrum für Synthetische Mikrobiologie, Philipps‐Universit?t Marburg, Hans‐Meerwein‐Strasse, 35032 Marburg (Germany) |
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| Abstract: | Two putative prenyltransferase genes, SAML0654 and Strvi8510, were identified in Streptomyces ambofaciens and Streptomyces violaceusniger, respectively. Their deduced products share 63 % sequence identity. Biochemical investigations with recombinant proteins demonstrated that L ‐tryptophan and derivatives, including D ‐tryptophan, 4‐, 5‐, 6‐ and 7‐methyl‐dl ‐tryptophan, were well accepted by both enzymes in the presence of DMAPP. Structural elucidation of the isolated products revealed regiospecific prenylation at C‐6 of the indole ring and proved unequivocally the identification of two very similar 6‐dimethylallyltryptophan synthases (6‐DMATS). Detailed biochemical investigations with SAML0654 proved L ‐tryptophan to be the best substrate (Km 18 μm, turnover 0.3 s?1). Incubation with different prenyl donors showed that they also accepted GPP and catalyzed the same specific prenylation. Utilizing GPP as a prenyl donor has not been reported for tryptophan prenyltransferases previously. Both enzymes also catalyzed prenylation of some hydroxynaphthalenes; this has not previously been described for bacterial indole prenyltransferases. Interestingly, SAML0654 transferred prenyl moieties onto the unsubstituted ring of hydroxynaphthalenes. |
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| Keywords: | dimethylallyltryptophan synthases enzymes hydroxynaphthalenes indole prenyltransferases natural products Streptomyces |
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