Characterization of a putative NsrR homologue in Streptomyces venezuelae reveals a new member of the Rrf2 superfamily.
Members of the Rrf2 superfamily of transcription factors are widespread in bacteria but their functions are largely unexplored. The few that have been characterized in detail sense nitric oxide (NsrR), iron limitation (RirA), cysteine availability (CymR) and the iron sulfur (Fe-S) cluster status of the cell (IscR). In this study we combined ChIP- and dRNA-seq with in vitro biochemistry to characterize a putative NsrR homologue in Streptomyces venezuelae. ChIP-seq analysis revealed that rather than regulating the nitrosative stress response like Streptomyces coelicolor NsrR, Sven6563 binds to a conserved motif at a different, much larger set of genes with a diverse range of functions, including a number of regulators, genes required for glutamine synthesis, NADH/NAD(P)H metabolism, as well as general DNA/RNA and amino acid/protein turn over. Our biochemical experiments further show that Sven6563 has a [2Fe-2S] cluster and that the switch between oxidized and reduced cluster controls its DNA binding activity in vitro. To our knowledge, both the sensing domain and the putative target genes are novel for an Rrf2 protein, suggesting Sven6563 represents a new member of the Rrf2 superfamily. Given the redox sensitivity of its Fe-S cluster we have tentatively named the protein RsrR for Redox sensitive response Regulator.
School of Biological Sciences, University of East Anglia, Norwich, Norwich Research Park, United Kingdom.
John T
JT
Munnoch
Centre for Molecular and Structural Biochemistry, School of Chemistry, University of East Anglia,Norwich, Norwich Research Park, United Kingdom.
Ma Teresa Pellicer
MT
Martinez
School of Biological Sciences, University of Essex, Wivenhoe Park, Colchester, United Kingdom.
Dimitri A
DA
Svistunenko
Centre for Molecular and Structural Biochemistry, School of Chemistry, University of East Anglia,Norwich, Norwich Research Park, United Kingdom.
Jason C
JC
Crack
Centre for Molecular and Structural Biochemistry, School of Chemistry, University of East Anglia,Norwich, Norwich Research Park, United Kingdom.
Nick E
NE
Le Brun
School of Biological Sciences, University of East Anglia, Norwich, Norwich Research Park, United Kingdom.
Matthew I
MI
Hutchings
D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D004269:DNA, Bacterial / Q000235:genetics / Q000378:metabolism; D007506:Iron-Sulfur Proteins / Q000235:genetics / Q000378:metabolism; D059372:Nucleotide Motifs; D011485:Protein Binding; D017386:Sequence Homology, Amino Acid; D013302:Streptomyces / Q000235:genetics / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism
D001426:Bacterial Proteins; D004269:DNA, Bacterial; D007506:Iron-Sulfur Proteins; D014157:Transcription Factors