Repression by Fur is not the main mechanism controlling the iron-inducible isiAB operon in the cyanobacterium Synechocystis sp. PCC 6803.

The iron deficiency-dependent regulation of isiAB transcription in Synechocystis sp. PCC 6803 was analyzed by fusion of modified isiAB promoter fragments to gfp and in vivo quantification of Gfp fluorescence. For the putative Fur box only a slight repressing impact on promoter activity could be shown.

Identification of genes essential for growth at high salt concentrations using salt-sensitive mutants of the cyanobacterium Synechocystis sp. strain PCC 6803.

A collection of 17 salt-sensitive mutants of the cyanobacterium Synechocystis sp. strain PCC 6803 was obtained by random cartridge mutagenesis. The genes coding for proteins essential for growth at high salt concentrations were mapped on the completely known genome sequence of this strain.