Natural variation in the microcystin synthetase operon mcyABC and impact on microcystin production in Microcystis strains.

ABSTRACT: Toxic Microcystis strains often produce several isoforms of the cyclic hepatotoxin microcystin, and more than 65 isoforms are known. This has been attributed to relaxed substrate specificity of the adenylation domain. Our results show that in addition to this, variability is also caused by genetic variation in the microcystin synthetase genes. Genetic characterization of a region of the adenylation domain in module mcyB1 resulted in identification of two groups of genetic variants in closely related Microcystis strains. Sequence analyses suggested that the genetic variation is due to recombination events between mcyB1 and the corresponding domains in mcyC. Each variant could be correlated to a particular microcystin isoform profile, as identified by matrix-assisted laser desorption ionizat

SUBMITTER: Mikalsen B 

PROVIDER: S-EPMC154389 | biostudies-literature | 2003 May

REPOSITORIES: biostudies-literature