title: Characterization of the nocardiopsin biosynthetic gene cluster reveals similarities to and differences from the rapamycin and FK-506 pathways.
abstract: Macrolide-pipecolate natural products, such as rapamycin (1) and FK-506 (2), are renowned modulators of FK506-binding proteins (FKBPs). The nocardiopsins, from Nocardiopsis sp. CMB-M0232, are the newest members of this structural class. Here, the biosynthetic pathway for nocardiopsins A-D (4-7) is revealed by cloning, sequencing, and bioinformatic analyses of the nsn gene cluster. In vitro evaluation of recombinant NsnL revealed that this lysine cyclodeaminase catalyzes the conversion of L-lysine into the L-pipecolic acid incorporated into 4 and 5. Bioinformatic analyses supported the conjecture that a linear nocardiopsin precursor is equipped with the hydroxy group required for macrolide closure in a previously unobserved manner by employing a P450 epoxidase (NsnF) and limonene epoxide hydrolase homologue (NsnG). The nsn cluster also encodes candidates for tetrahydrofuran group biosynthesis. The nocardiopsin pathway provides opportunities for engineering of FKBP-binding metabolites and for probing new enzymology in nature's polyketide tailoring arsenal.
authors.affiliation: Chemistry Department, University of North Florida, 1 UNF Drive, Jacksonville, FL 32224 (USA).
authors.forename: Dana M
authors.initials: DM
authors.lastname: Bis
authors.forename: Yang H
authors.initials: YH
authors.lastname: Ban
authors.forename: Elle D
authors.initials: ED
authors.lastname: James
authors.forename: Norah
authors.initials: N
authors.lastname: Alqahtani
authors.forename: Rajesh
authors.initials: R
authors.lastname: Viswanathan
authors.forename: Amy L
authors.initials: AL
authors.lastname: Lane
mesh_terms: D000192:Actinomycetales / Q000201:enzymology / Q000235:genetics / Q000378:metabolism; D000595:Amino Acid Sequence; D000642:Ammonia-Lyases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D055162:Biocatalysis; D003001:Cloning, Molecular; D019295:Computational Biology; D005663:Furans / Q000378:metabolism; D008969:Molecular Sequence Data; D005810:Multigene Family; D010875:Pipecolic Acids / Q000378:metabolism; D020123:Sirolimus / Q000378:metabolism*; D016559:Tacrolimus / Q000378:metabolism*
chemical_list: D005663:Furans; D010875:Pipecolic Acids; C018674:tetrahydrofuran; D000642:Ammonia-Lyases; C109507:lysine cyclodeaminase; C031345:pipecolic acid; D020123:Sirolimus; D016559:Tacrolimus
keywords: biosynthesis; macrolides; natural products; pipecolic acid; polyketides