title: Computational-guided discovery and characterization of a sesquiterpene synthase from Streptomyces clavuligerus.
abstract: 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.
authors.affiliation: Department of Chemistry, University of Utah, Salt Lake City, UT 84112;
authors.forename: Jeng-Yeong
authors.initials: JY
authors.lastname: Chow
authors.affiliation: Department of Pharmaceutical Chemistry, School of Pharmacy, University of California, San Francisco, CA 94158; California Institute for Quantitative Biomedical Research, University of California, San Francisco, CA 94158; and.
authors.forename: Bo-Xue
authors.initials: BX
authors.lastname: Tian
authors.affiliation: Department of Chemistry, University of Utah, Salt Lake City, UT 84112;
authors.forename: Gurusankar
authors.initials: G
authors.lastname: Ramamoorthy
authors.affiliation: Department of Biochemistry, Albert Einstein College of Medicine, Bronx, NY 10461.
authors.forename: Brandan S
authors.initials: BS
authors.lastname: Hillerich
authors.affiliation: Department of Biochemistry, Albert Einstein College of Medicine, Bronx, NY 10461.
authors.forename: Ronald D
authors.initials: RD
authors.lastname: Seidel
authors.affiliation: Department of Biochemistry, Albert Einstein College of Medicine, Bronx, NY 10461.
authors.forename: Steven C
authors.initials: SC
authors.lastname: Almo
authors.affiliation: Department of Pharmaceutical Chemistry, School of Pharmacy, University of California, San Francisco, CA 94158; California Institute for Quantitative Biomedical Research, University of California, San Francisco, CA 94158; and matt.jacobson@ucsf.edu poulter@chemistry.utah.edu.
authors.forename: Matthew P
authors.initials: MP
authors.lastname: Jacobson
authors.affiliation: Department of Chemistry, University of Utah, Salt Lake City, UT 84112; matt.jacobson@ucsf.edu poulter@chemistry.utah.edu.
authors.forename: C Dale
authors.initials: CD
authors.lastname: Poulter
mesh_terms: D000465:Algorithms; D019883:Alkyl and Aryl Transferases / Q000737:chemistry*; D002244:Carbon / Q000737:chemistry; D020134:Catalytic Domain; D002412:Cations; D016000:Cluster Analysis; D019295:Computational Biology; D003198:Computer Simulation; D017434:Protein Structure, Tertiary; D012984:Software; D013302:Streptomyces / Q000201:enzymology*; D013329:Structure-Activity Relationship
chemical_list: D002412:Cations; D002244:Carbon; D019883:Alkyl and Aryl Transferases; C108877:terpene synthase
keywords: annotation; cyclase; sesquiterpene; structure-function