Thiazolstrukturen in Cyanobakterien - Evolutionäre Zusammenhänge zwischen Cyanobakterien und Myxobakterien (II)

Cyanobacteria produce a manyfold spectrum of unique secondary metabolites, but they also produce metabolites that indicate a relationship to myxobacterial compounds. A prominent example for such a structural homology are the mirabazoles and tantazoles, polythiazolines isolated from the terrestric cyanobacterium Scytonema mirabile that show high similarity to thiangazoles from Polyangium spec. Further indication for a relationship between myxobacterial and cyanobacterial polyketide synthases (PKS) and nonribosomal peptide synthetases (NRPS) arises from analyses of the genome of the terrestric cyanobacterial strain Nostoc punctiforme. The genome of this symbiotic cyanobacterial strain, in contrast to other cyanobacterial genomes, possesses a remarkable number of genes encoding PKSs and NRPSs with high similarities to myxobacterial enzymes. One of the gene clusters encodes a biosynthesis complex that presumably synthesises a polyketide structure containing a thiazole moiety. The aims of this project are to show 1) Is there a structural relationship between the cyanometabolite and known myxobacterial metabolites? 2) How similar are mechanistic and biochemical features of such related biosynthesis enzymes 3) Are similar biosynthetic pathways in different bacteria under the control of similar regulatory elements? 4) Can we draw general conclusions about the evolution of bacterial PKS and NRPS pathways from that?