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FAD-sequestering proteins protect mycobacteria against hypoxic and oxidative stress

Harold, Liam K.; Antoney, James; Ahmed, Fathimath; Hards, Kiel; Carr, Paul D.; Rapson, Trevor D.; Greening, Chris; Jackson, Colin; Cook, Greg

Description

The ability to persist in the absence of growth triggered by low oxygen levels is a critical process for the survival of mycobacterial species in many environmental niches. MSMEG_5243 (fsq), a gene of unknown function in Mycobacterium smegmatis, is up-regulated in response to hypoxia and regulated by DosRDosS/DosT, an oxygen- and redox-sensing two-component system that is highly conserved in mycobacteria. In this communication, we demonstrate that MSMEG_5243 is a flavin-sequestering protein and...[Show more]

dc.contributor.authorHarold, Liam K.
dc.contributor.authorAntoney, James
dc.contributor.authorAhmed, Fathimath
dc.contributor.authorHards, Kiel
dc.contributor.authorCarr, Paul D.
dc.contributor.authorRapson, Trevor D.
dc.contributor.authorGreening, Chris
dc.contributor.authorJackson, Colin
dc.contributor.authorCook, Greg
dc.date.accessioned2020-07-07T00:57:42Z
dc.identifier.issn1083-351X
dc.identifier.urihttp://hdl.handle.net/1885/205860
dc.description.abstractThe ability to persist in the absence of growth triggered by low oxygen levels is a critical process for the survival of mycobacterial species in many environmental niches. MSMEG_5243 (fsq), a gene of unknown function in Mycobacterium smegmatis, is up-regulated in response to hypoxia and regulated by DosRDosS/DosT, an oxygen- and redox-sensing two-component system that is highly conserved in mycobacteria. In this communication, we demonstrate that MSMEG_5243 is a flavin-sequestering protein and henceforth refer to it as Fsq. Using an array of biochemical and structural analyses, we show that Fsq is a member of the diverse superfamily of flavin- and deazaflavin-dependent oxidoreductases (FDORs) and is widely distributed in mycobacterial species. We created a markerless deletion mutant of fsq and demonstrate that fsq is required for cell survival during hypoxia. Using fsq deletion and overexpression, we found that fsq enhances cellular resistance to hydrogen peroxide treatment. The X-ray crystal structure of Fsq, solved to 2.7 Å, revealed a homodimeric organization with FAD bound noncovalently. The Fsq structure also uncovered no potential substrate-binding cavities, as the FAD is fully enclosed, and electrochemical studies indicated that the Fsq:FAD complex is relatively inert and does not share common properties with electron-transfer proteins. Taken together, our results suggest that Fsq reduces the formation of reactive oxygen species (ROS) by sequestering free FAD during recovery from hypoxia, thereby protecting the cofactor from undergoing autoxidation to produce ROS. This finding represents a new paradigm in mycobacterial adaptation to hypoxia.
dc.description.sponsorshipThis work was supported by the Maurice Wilkins Centre for Molecular Biodiscovery and the Marsden Fund, Royal Society, New Zealand. This work was also supported by a University of Otago Doctoral Scholarship and a Sandy Smith Scholarship (to L. K. H.) and by a CSIRO OCE Postdoctoral Fellowship, ARC DECRA Fellowship DE170100310, and NHMRC New Investigator Grant APP1139832 (to C. G.). In addition, this work was supported by NHMRC Project Grant APP1128929 (to C. J. J., C. G., and G. M. C.).
dc.format.mimetypeapplication/pdf
dc.language.isoen_AU
dc.publisherAmerican Society for Biochemistry and Molecular Biology Inc
dc.rights© 2019 Harold et al.
dc.sourceJournal of Biological Chemistry
dc.subjectreactive oxygen species (ROS)
dc.subjectmycobacteria
dc.subjectMycobacterium smegmatis
dc.subjecthypoxia
dc.subjectflavin
dc.subjectflavin adenine dinucleotide (FAD)
dc.subjectbacterial genetics
dc.subjectoxidative stress
dc.subjectanoxia
dc.subjectdos regulon
dc.subjectDosR
dc.subjectoxidoreductase
dc.titleFAD-sequestering proteins protect mycobacteria against hypoxic and oxidative stress
dc.typeJournal article
local.description.notesImported from ARIES
local.identifier.citationvolume294
dc.date.issued2018-12-19
local.identifier.absfor030406 - Proteins and Peptides
local.identifier.ariespublicationu3102795xPUB2203
local.publisher.urlhttps://www.jbc.org/
local.type.statusPublished Version
local.contributor.affiliationHarold, Liam K., University of Otago
local.contributor.affiliationAntoney, James, College of Science, ANU
local.contributor.affiliationAhmed, Fathimath, College of Science, ANU
local.contributor.affiliationHards, Kiel, University of Otago
local.contributor.affiliationCarr, Paul D., College of Science, ANU
local.contributor.affiliationRapson, Trevor D., CSIRO
local.contributor.affiliationGreening, Chris, The Commonwealth Scientific and Industrial Research Organisation
local.contributor.affiliationJackson, Colin, College of Science, ANU
local.contributor.affiliationCook, Greg, University of Otago
local.description.embargo2037-12-31
dc.relationhttp://purl.org/au-research/grants/arc/DE170100310
dc.relationhttp://purl.org/au-research/grants/nhmrc/1139832
local.bibliographicCitation.issue8
local.bibliographicCitation.startpage2903
local.bibliographicCitation.lastpage2912
local.identifier.doi10.1074/jbc.RA118.006237
local.identifier.absseo970103 - Expanding Knowledge in the Chemical Sciences
dc.date.updated2020-05-17T08:22:09Z
local.identifier.scopusID2-s2.0-85062026052
local.identifier.thomsonID4.59602E+11
CollectionsANU Research Publications

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