Computational-guided discovery and characterization of a sesquiterpene synthase from Streptomyces clavuligerus.
Terpenoids are a large structurally diverse group of natural products with an array of functions in their hosts. The large amount of genomic information from recent sequencing efforts provides opportunities and challenges for the functional assignment of terpene synthases that construct the carbon skeletons of these compounds. Inferring function from the sequence and/or structure of these enzymes is not trivial because of the large number of possible reaction channels and products. We tackle this problem by developing an algorithm to enumerate possible carbocations derived from the farnesyl cation, the first reactive intermediate of the substrate, and evaluating their steric and electrostatic compatibility with the active site. The homology model of a putative pentalenene synthase (Uniprot: B5GLM7) from Streptomyces clavuligerus was used in an automated computational workflow for product prediction. Surprisingly, the workflow predicted a linear triquinane scaffold as the top product skeleton for B5GLM7. Biochemical characterization of B5GLM7 reveals the major product as (5S,7S,10R,11S)-cucumene, a sesquiterpene with a linear triquinane scaffold. To our knowledge, this is the first documentation of a terpene synthase involved in the synthesis of a linear triquinane. The success of our prediction for B5GLM7 suggests that this approach can be used to facilitate the functional assignment of novel terpene synthases.
['Chow|Jeng-Yeong|JY|', 'Tian|Bo-Xue|BX|', 'Ramamoorthy|Gurusankar|G|', 'Hillerich|Brandan S|BS|', 'Seidel|Ronald D|RD|', 'Almo|Steven C|SC|', 'Jacobson|Matthew P|MP|', 'Poulter|C Dale|CD|']
D000465:Algorithms D019883:Alkyl and Aryl Transferases D002244:Carbon D020134:Catalytic Domain D002412:Cations D016000:Cluster Analysis D019295:Computational Biology D003198:Computer Simulation D017434:Protein Structure, Tertiary D012984:Software D013302:Streptomyces D013329:Structure-Activity Relationship
sesquiterpene annotation cyclase structure-function