Comparative analysis of the D-lysergic acid module LPS2 in the two distinct assembly lines of simple D-lysergic acid amides and complex D-lysergic acid peptides (ergopeptines) in Claviceps purpurea or Claviceps paspali

ULLRICH KELLER
Fakultät II, Institut für Chemie
Technische Universität Berlin
Arbeitsgruppe Biochemie
Franklinstraße 29
D-10587 Berlin-Charlottenburg
ullrich.keller@tu-berlin.de
http://www.chemie.tu-berlin.de

The ergot alkaloids can be divided into two classes of compounds: the clavines and the therapeutically important D-lysergic acid amides which both are produced by ergot fungi. The D-lysergic acid amides contain as amide component either simple amino alcohols (as in ergometrine) or modified tripeptide chains (ergopeptines). Biosynthetically, D-lysergic acid is derived from the clavine alkaloids, however, the ability to produce clavines or the different D-lysergic acid derived alkaloids appears to be genetically determined among the numerous and highly diverse ergot fungi. The cloning of the ergot alkaloid biosynthesis gene cluster from Claviceps purpurea which produces ergopeptines will facilitate to clarify the functions of the various genes encoding steps in clavine and D-lysergic acid amide biosynthesis. Comparative genetic and biochemical analysis of strains producing less complex alkaloids such as simple D-lysergic acid amides or clavines will show how the structures of their biosynthetic gene clusters are correlated to the products formed in these strains. The structural comparison of these clusters will show how they evolved and arose by gene modifications or deletions of essential steps of the most 'advanced' gene cluster in C. purpurea. Special interest lies on the formation of different D-lysergic acid amides: in C. purpurea ergopeptines are assembled nonribosomally by LPS 1, a trimodular NRPS and LPS 2 , a monomodular NRPS activating D-lysergic acid. Current work performed in this project indicates that LPS 2 is also involved in the assembly of peptide precursor of the simple D-lysergic acid amide ergometrine which is produced by C. purpurea or C. paspali. In vitro data suggest in C. purpurea a timely coordinated synthesis of both ergopeptine and ergometrine synthesis with LPS 2 as a common enzyme component of two different peptide assembly lines while in C. paspali the ergopeptine assembly line would be absent.

References
Correia,T., Grammel,N., Ortel,I., Keller,U., Tudzynski,P. (2003) Molecular cloning and analysis of the ergopeptine assembly system in the ergot fungus Claviceps purpurea.Chem Biol. 10:1281-92.

Schmoock,G., Pfennig,F., Jewiarz,J., Schlumbohm,W., Laubinger,W., Schauwecker,F., Keller,U. (2005) Functional cross-talk between fatty acid synthesis and nonribosomal peptide synthesis in quinoxaline antibiotic-producing streptomycetes. J. Biol.Chem. 280, 4339-49.

Schwartz,D., Grammel,N., Heinzelmann, E., Keller,U., Wohlleben, W. (2005) Phosphinothricin tripeptide synthetases in Streptomyces viridochromogenes Tu494. Antimicrob Agents Chemother.49:4598-607.

Haarmann,T., Ortel, I., Tudzynski P., Keller,U. (2006) Identification of the cytochrome P450 monooxygenase that bridges the clavine and ergoline alkaloid pa thways.Chembiochem. 7:645-52.

Ortel, I., Keller, U. (2007) Partionining of the D-lysergic acid module in two independent nonribosomal assembly lines forming different of D-lysergic acid alkloids of amide/peptide type (submitted).

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