The role of flavodiiron proteins from Synechocystis sp. PCC 6803 under nitrosative and oxidative stresses.

ITQB PhD Seminars

Title: The role of flavodiiron proteins from Synechocystis sp. PCC 6803 under nitrosative and oxidative stresses.

Speaker: Vera Gonçalves

Laboratory: Metalloproteins and Bioenergetics

Abstract
Cyanobacteria are a large and widely spread group of photoautotrophic prokaryotes able to carry out oxygenic photosynthesis.
The genome of Synechocystis sp. PCC 6803, the organism studied in this work, has four genes coding for flavodiiron proteins (FDPs) (flv1, flv2, flv3 and flv4).
FDPs are a family of nitric oxide and/or oxygen reducing enzymes, having a common core, formed by a metallo--lactamase-like domain containing a diiron catalytic site, fused to a C-terminal flavodoxin-like domain, harboring a flavin mononucleotide (FMN) moiety. The cyanobacterial FDPs comprise an extra C-terminal domain homologous to NAD(P)H:flavin oxidoreductases.
We set out to investigate the function and role of the various Synechocystis FDPs in nitric oxide (NO) and oxygen (O2) detoxification. To this end, we have constructed three Synechocystis mutant strains knocked-out in the genes flv1, flv3 and flv2 plus flv4. Subsequently, we have analyzed the phenotypes, chlorophyll and reactive oxygen species levels produced by these mutant strains and the transcriptional levels of the flavodiiron genes under different conditions of nitrosative and oxidative stresses. Also, we used an Escherichia coli FDP-deletion strain to further assess, by complementation assays, the function of each of the Synechocystis flavodiiron proteins. The results show that the flv1 gene has a role under oxidative stress, the flv2 gene has a role under oxidative and nitrosative stresses while the flv3 gene has a role under nitrosative stress conditions.

Short CV
1999 – 2004: Degree in Applied Chemistry by Faculdade de Ciências e Tecnologia da Universidade Nova de Lisboa
2004: Training year at the Molecular Genetics of Microbial Resistance Lab - ITQB
2005 - 2006: Research student at the Molecular Genetics of Microbial Resistance Lab - ITQB
Out 2006 to now: PhD student at the Molecular Genetics of Microbial Resistance Lab and at the Metalloproteins and Bioenergetics Lab