Rv1460, a SufR homologue, is a repressor of the suf operon in Mycobacterium tuberculosis

Danicke Willemse; Brandon Weber; Laura Masino; Robin M Warren; Salvatore Adinolfi; Annalisa Pastore; Monique J Williams

doi:10.1371/journal.pone.0200145

Rv1460, a SufR homologue, is a repressor of the suf operon in Mycobacterium tuberculosis

PLoS One. 2018 Jul 6;13(7):e0200145. doi: 10.1371/journal.pone.0200145. eCollection 2018.

Authors

Danicke Willemse¹, Brandon Weber², Laura Masino³, Robin M Warren¹, Salvatore Adinolfi⁴, Annalisa Pastore⁵, Monique J Williams¹

Affiliations

¹ DST-NRF Centre of Excellence for Biomedical Tuberculosis Research; South African Medical Research Council Centre for Tuberculosis Research; Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences, Stellenbosch University, Tygerberg, South Africa.
² Electron Microscope Unit, University of Cape Town, Cape Town, South Africa.
³ Structural Biology Science Technology Platform, The Francis Crick Institute, London, United Kingdom.
⁴ Pharmaceutical Science and Technology, University of Turin, Turin, Italy.
⁵ Department of Basic and Clinical Neuroscience, Maurice Wohl Institute, King's College London, London, United Kingdom.

Abstract

Iron-sulphur (Fe-S) clusters are ubiquitous co-factors which require multi-protein systems for their synthesis. In Mycobacterium tuberculosis, the Rv1460-Rv1461-Rv1462-Rv1463-csd-Rv1465-Rv1466 operon (suf operon) encodes the primary Fe-S cluster biogenesis system. The first gene in this operon, Rv1460, shares homology with the cyanobacterial SufR, which functions as a transcriptional repressor of the sufBCDS operon. Rv1460's function in M. tuberculosis has however not been determined. In this study, we demonstrate that M. tuberculosis mutants lacking a functional Rv1460 protein are impaired for growth under standard culture conditions. Elevated expression of Rv1460 and Rv1461 was observed in the mutant, implicating Rv1460 in the regulation of the suf operon. Binding of an Fe-S cluster to purified recombinant Rv1460 was confirmed by UV-visible spectroscopy and circular dichroism. Furthermore, three conserved cysteine residues, C203, C216 and C244, proposed to provide ligands for the coordination of an Fe-S cluster, were shown to be required for the function of Rv1460 in M. tuberculosis. Rv1460 therefore seems to be functionally analogous to cyanobacterial SufR.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Amino Acid Sequence
Bacterial Proteins / chemistry
Bacterial Proteins / genetics*
Bacterial Proteins / metabolism*
Binding Sites / genetics
Conserved Sequence
Cyanobacteria / genetics
Cyanobacteria / metabolism
Gene Deletion
Genes, Bacterial*
Humans
Iron-Sulfur Proteins / chemistry
Iron-Sulfur Proteins / genetics*
Iron-Sulfur Proteins / metabolism*
Mutation
Mycobacterium tuberculosis / genetics*
Mycobacterium tuberculosis / growth & development
Mycobacterium tuberculosis / metabolism*
Operon
Promoter Regions, Genetic
Recombinant Proteins / chemistry
Recombinant Proteins / genetics
Recombinant Proteins / metabolism
Repressor Proteins / chemistry
Repressor Proteins / genetics*
Repressor Proteins / metabolism*

Substances

Bacterial Proteins
Iron-Sulfur Proteins
Recombinant Proteins
Repressor Proteins

Grants and funding

We acknowledge the generous support of Professor Paul van Helden, the South African Medical Research Council (SAMRC) Centre for Tuberculosis Research and the Stellenbosch University node of the DST/National Research Foundation (NRF) Centre of Excellence for Biomedical TB Research. This work was supported by a Research Career Award (grant #91424 to MJW) from the NRF and a Researcher Links travel award from the Newton fund (to MJW). The content is solely the responsibility of the authors and does not necessarily represent the official views of the SAMRC or NRF. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.