The world's first wiki where authorship really matters (Nature Genetics, 2008). Due credit and reputation for authors. Imagine a global collaborative knowledge base for original thoughts. Search thousands of articles and collaborate with scientists around the globe.

wikigene or wiki gene protein drug chemical gene disease author authorship tracking collaborative publishing evolutionary knowledge reputation system wiki2.0 global collaboration genes proteins drugs chemicals diseases compound
Hoffmann, R. A wiki for the life sciences where authorship matters. Nature Genetics (2008)
 
 
 
 
 

Expression and mechanistic analysis of a germacradienol synthase from Streptomyces coelicolor implicated in geosmin biosynthesis.

The PCR has been used to amplify a 2,181-bp ORF from Streptomyces coelicolor A3(2), designated SC9B1.20 (= SCO6073), encoding a protein of 726 amino acids and showing significant sequence similarity at the deduced amino acid level in both the N-terminal and C-terminal halves to the known sesquiterpene synthase pentalenene synthase. The full-length recombinant protein was expressed at high levels in Escherichia coli and shown to catalyze the Mg(2+)-dependent conversion of farnesyl diphosphate to the sesquiterpene alcohol (4S, 7R)-germacra-1 (10)E, 5E-diene-11-ol. The enzymatic cyclization had a k(cat) of 6.2 +/- 0.5 x 10(-3) s(-1) and a K(m) for farnesyl diphosphate of 62 +/- 8 nM. Expression of the N-terminal (366 amino acids) domain of the SC9B1.20 protein also gave a fully functional cyclase which converted farnesyl diphosphate to the identical sesquiterpene alcohol with a slightly lower k(cat) of 3.2 +/- 0.4 x 10(-3) s(-1) and a twofold greater k(m) of 115 +/- 14 nM. By contrast, the expressed C-terminal domain of SC9B1.20 had no farnesyl diphosphate cyclase activity. The formation of the germacradienol seems to be the committed step in the formation of geosmin, the characteristic odoriferous constituent of Streptomyces species.[1]

References

 
WikiGenes - Universities