Cysteine Mutational Studies Provide Insight into a Thiol-Based Redox Switch Mechanism of Metal and DNA Binding in FurA from Anabaena sp. PCC 7120.

ABSTRACT:

Aims

The ferric uptake regulator (Fur) is the main transcriptional regulator of genes involved in iron homeostasis in most prokaryotes. FurA from Anabaena sp. PCC 7120 contains five cysteine residues, four of them arranged in two redox-active CXXC motifs. The protein needs not only metal but also reducing conditions to remain fully active in vitro. Through a mutational study of the cysteine residues present in FurA, we have investigated their involvement in metal and DNA binding.

Results

Residue C¹⁰¹ that belongs to a conserved CXXC motif plays an essential role in both metal and DNA binding activities in vitro. Substitution of C¹⁰¹ by serine impairs DNA and metal binding abilities of FurA. Isothermal titration calorimetry measurements show that the red

SUBMITTER: Botello-Morte L 

PROVIDER: S-EPMC4744886 | biostudies-literature | 2016 Feb

REPOSITORIES: biostudies-literature