Fur from Microcystis aeruginosa binds in vitro promoter regions of the microcystin biosynthesis gene cluster.
Promoter regions of the mcy operon from Microcystis aeruginosa PCC7806, which is responsible for microcystin synthesis in this organism, exhibit sequences that are similar to the sequences recognized by Fur (ferric uptake regulator). This DNA-binding protein is a sensor of iron availability and oxidative stress. In the presence of Fe(2+), a dimer of Fur binds the iron-boxes in their target genes, repressing their expression. When iron is absent the expression of those gene products is allowed. Here, we show that Fur from M. aeruginosa binds in vitro promoter regions of several mcy genes, which suggests that Fur might regulate, among other factors, microcystin synthesis. The binding affinity is increased by the presence of metal and DTT, suggesting a response to iron availability and redox status of the cell.
Martin-Luna
Beatriz
B
Departamento de Bioquimica y Biologia Molecular y Celular, Facultad de Ciencias, and BIFI, Universidad de Zaragoza, Spain.
Sevilla
Emma
E
Hernandez
José A
JA
Bes
M Teresa
MT
Fillat
Maria F
MF
Peleato
M Luisa
ML
D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D001483:Base Sequence; D052998:Microcystins; D046931:Microcystis / Q000235:genetics*; D008969:Molecular Sequence Data; D005810:Multigene Family; D010456:Peptides, Cyclic / Q000096:biosynthesis* / Q000235:genetics*; D011401:Promoter Regions, Genetic; D012097:Repressor Proteins / Q000235:genetics / Q000378:metabolism*
D001426:Bacterial Proteins; D052998:Microcystins; D010456:Peptides, Cyclic; D012097:Repressor Proteins; C068477:ferric uptake regulating proteins, bacterial; C078588:microcystin