Methionine Biosynthesis in Is Tightly Controlled by a Hierarchical Network Involving an Initiator tRNA-Specific T-box Riboswitch
In line with the key role of methionine in protein biosynthesis initiation and many cellular processes most microorganisms have evolved mechanisms to synthesize methionine de novo. Here we demonstrate that, in the bacterial pathogen Staphylococcus aureus, a rare combination of stringent response-controlled CodY activity, T-box riboswitch and mRNA decay mechanisms regulate the synthesis and stability of methionine biosynthesis metICFE-mdh mRNA. In contrast to other Bacillales which employ S-box riboswitches to control methionine biosynthesis, the S. aureus metICFE-mdh mRNA is preceded by a 5′-untranslated met leader RNA harboring a T-box riboswitch. Interestingly, this T-box riboswitch is revealed to specifically interact with uncharged initiator formylmethionyl-tRNA (tRNAifMet) while binding of elongator tRNAMet proved to be weak, suggesting a putative additional function of the system in translation initiation control. met leader RNA/metICFE-mdh operon expression is under the control of the repressor CodY which binds upstream of the met leader RNA promoter. As part of the metabolic emergency circuit of the stringent response, methionine depletion activates RelA-dependent (p)ppGpp alarmone synthesis, releasing CodY from its binding site and thereby activating the met leader promoter. Our data further suggest that subsequent steps in metICFE-mdh transcription are tightly controlled by the 5′ met leader-associated T-box riboswitch which mediates premature transcription termination when methionine is present. If methionine supply is limited, and hence tRNAifMet becomes uncharged, full-length met leader/metICFE-mdh mRNA is transcribed which is rapidly degraded by nucleases involving RNase J2. Together, the data demonstrate that staphylococci have evolved special mechanisms to prevent the accumulation of excess methionine. We hypothesize that this strict control might reflect the limited metabolic capacities of staphylococci to reuse methionine as, other than Bacillus, staphylococci lack both the methionine salvage and polyamine synthesis pathways. Thus, methionine metabolism might represent a metabolic Achilles' heel making the pathway an interesting target for future anti-staphylococcal drug development.
Vyšlo v časopise:
Methionine Biosynthesis in Is Tightly Controlled by a Hierarchical Network Involving an Initiator tRNA-Specific T-box Riboswitch. PLoS Pathog 9(9): e32767. doi:10.1371/journal.ppat.1003606
Kategorie:
Research Article
prolekare.web.journal.doi_sk:
https://doi.org/10.1371/journal.ppat.1003606
Souhrn
In line with the key role of methionine in protein biosynthesis initiation and many cellular processes most microorganisms have evolved mechanisms to synthesize methionine de novo. Here we demonstrate that, in the bacterial pathogen Staphylococcus aureus, a rare combination of stringent response-controlled CodY activity, T-box riboswitch and mRNA decay mechanisms regulate the synthesis and stability of methionine biosynthesis metICFE-mdh mRNA. In contrast to other Bacillales which employ S-box riboswitches to control methionine biosynthesis, the S. aureus metICFE-mdh mRNA is preceded by a 5′-untranslated met leader RNA harboring a T-box riboswitch. Interestingly, this T-box riboswitch is revealed to specifically interact with uncharged initiator formylmethionyl-tRNA (tRNAifMet) while binding of elongator tRNAMet proved to be weak, suggesting a putative additional function of the system in translation initiation control. met leader RNA/metICFE-mdh operon expression is under the control of the repressor CodY which binds upstream of the met leader RNA promoter. As part of the metabolic emergency circuit of the stringent response, methionine depletion activates RelA-dependent (p)ppGpp alarmone synthesis, releasing CodY from its binding site and thereby activating the met leader promoter. Our data further suggest that subsequent steps in metICFE-mdh transcription are tightly controlled by the 5′ met leader-associated T-box riboswitch which mediates premature transcription termination when methionine is present. If methionine supply is limited, and hence tRNAifMet becomes uncharged, full-length met leader/metICFE-mdh mRNA is transcribed which is rapidly degraded by nucleases involving RNase J2. Together, the data demonstrate that staphylococci have evolved special mechanisms to prevent the accumulation of excess methionine. We hypothesize that this strict control might reflect the limited metabolic capacities of staphylococci to reuse methionine as, other than Bacillus, staphylococci lack both the methionine salvage and polyamine synthesis pathways. Thus, methionine metabolism might represent a metabolic Achilles' heel making the pathway an interesting target for future anti-staphylococcal drug development.
Zdroje
1. HidronAI, EdwardsJR, PatelJ, HoranTC, SievertDM, et al. (2008) NHSN annual update: antimicrobial-resistant pathogens associated with healthcare-associated infections: annual summary of data reported to the National Healthcare Safety Network at the Centers for Disease Control and Prevention, 2006–2007. Infect Control Hosp Epidemiol 29: 996–1011.
2. ChambersHF, DeleoFR (2009) Waves of resistance: Staphylococcus aureus in the antibiotic era. Nat Rev Microbiol 7: 629–641.
3. SomervilleGA, ProctorRA (2009) At the crossroads of bacterial metabolism and virulence factor synthesis in Staphylococci. Microbiol Mol Biol Rev 73: 233–248.
4. ParveenN, CornellKA (2011) Methylthioadenosine/S-adenosylhomocysteine nucleosidase, a critical enzyme for bacterial metabolism. Mol Microbiol 79: 7–20.
5. RodionovDA, VitreschakAG, MironovAA, GelfandMS (2004) Comparative genomics of the methionine metabolism in Gram-positive bacteria: a variety of regulatory systems. Nucleic Acids Res 32: 3340–3353.
6. Gutierrez-PreciadoA, HenkinTM, GrundyFJ, YanofskyC, MerinoE (2009) Biochemical features and functional implications of the RNA-based T-box regulatory mechanism. Microbiol Mol Biol Rev 73: 36–61.
7. GrundyFJ, HenkinTM (1998) The S box regulon: a new global transcription termination control system for methionine and cysteine biosynthesis genes in Gram-positive bacteria. Mol Microbiol 30: 737–749.
8. VitreschakAG, MironovAA, LyubetskyVA, GelfandMS (2008) Comparative genomic analysis of T-box regulatory systems in bacteria. RNA 14: 717–735.
9. GreenNJ, GrundyFJ, HenkinTM (2010) The T box mechanism: tRNA as a regulatory molecule. FEBS Lett 584: 318–324.
10. MajerczykCD, DunmanPM, LuongTT, LeeCY, SadykovMR, et al. (2010) Direct targets of CodY in Staphylococcus aureus. J Bacteriol 192: 2861–2877.
11. PohlK, FrancoisP, StenzL, SchlinkF, GeigerT, et al. (2009) CodY in Staphylococcus aureus: a regulatory link between metabolism and virulence gene expression. J Bacteriol 191: 2953–2963.
12. GeigerT, GoerkeC, FritzM, SchäferT, OhlsenK, et al. (2010) Role of the (p)ppGpp synthase RSH, a RelA/SpoT homolog, in stringent response and virulence of Staphylococcus aureus. Infect Immun 78: 1873–1883.
13. Ratnayake-LecamwasamM, SerrorP, WongKW, SonensheinAL (2001) Bacillus subtilis CodY represses early-stationary-phase genes by sensing GTP levels. Genes Dev 15: 1093–1103.
14. ShiversRP, SonensheinAL (2004) Activation of the Bacillus subtilis global regulator CodY by direct interaction with branched-chain amino acids. Mol Microbiol 53: 599–611.
15. NovichkovPS, LaikovaON, NovichkovaES, GelfandMS, ArkinAP, et al. (2010) RegPrecise: a database of curated genomic inferences of transcriptional regulatory interactions in prokaryotes. Nucleic Acids Res 38: D111–118.
16. BrinsmadeSR, KleijnRJ, SauerU, SonensheinAL (2010) Regulation of CodY activity through modulation of intracellular branched-chain amino acid pools. J Bacteriol 192: 6357–6368.
17. SerganovA, PatelDJ (2007) Ribozymes, riboswitches and beyond: regulation of gene expression without proteins. Nat Rev Genet 8: 776–790.
18. MäderU, ZigL, KretschmerJ, HomuthG, PutzerH (2008) mRNA processing by RNases J1 and J2 affects Bacillus subtilis gene expression on a global scale. Mol Microbiol 70: 183–196.
19. LioliouE, SharmaCM, CaldelariI, HelferAC, FechterP, et al. (2012) Global regulatory functions of the Staphylococcus aureus endoribonuclease III in gene expression. PLoS Genet 8: e1002782.
20. JoshiGS, SpontakJS, KlapperDG, RichardsonAR (2011) Arginine catabolic mobile element encoded speG abrogates the unique hypersensitivity of Staphylococcus aureus to exogenous polyamines. Mol Microbiol 82: 9–20.
21. SekowskaA, DenervaudV, AshidaH, MichoudK, HaasD, et al. (2004) Bacterial variations on the methionine salvage pathway. BMC Microbiol 4: 9.
22. HulloMF, AugerS, SoutourinaO, BarzuO, YvonM, et al. (2007) Conversion of methionine to cysteine in Bacillus subtilis and its regulation. J Bacteriol 189: 187–197.
23. ChaffinDO, TaylorD, SkerrettSJ, RubensCE (2012) Changes in the Staphylococcus aureus transcriptome during early adaptation to the lung. PLoS One 7: e41329.
24. PietiainenM, FrancoisP, HyyrylainenHL, TangomoM, SassV, et al. (2009) Transcriptome analysis of the responses of Staphylococcus aureus to antimicrobial peptides and characterization of the roles of vraDE and vraSR in antimicrobial resistance. BMC Genomics 10: 429.
25. NagarajanV, ElasriMO (2007) SAMMD: Staphylococcus aureus microarray meta-database. BMC Genomics 8: 351.
26. OchsnerUA, YoungCL, StoneKC, DeanFB, JanjicN, et al. (2005) Mode of action and biochemical characterization of REP8839, a novel inhibitor of methionyl-tRNA synthetase. Antimicrob Agents Chemother 49: 4253–4262.
27. AnupamR, NayekA, GreenNJ, GrundyFJ, HenkinTM, et al. (2008) 4,5-Disubstituted oxazolidinones: High affinity molecular effectors of RNA function. Bioorg Med Chem Lett 18: 3541–3544.
28. AnupamR, DenapoliL, MuchenditsiA, HinesJV (2008) Identification of neomycin B-binding site in T box antiterminator model RNA. Bioorg Med Chem 16: 4466–4470.
29. LagojaIM, HerdewijnP (2007) Use of RNA in drug design. Expert Opin Drug Discov 2: 889–903.
30. SampsonJR, UhlenbeckOC (1988) Biochemical and physical characterization of an unmodified yeast phenylalanine transfer RNA transcribed in vitro. Proc Natl Acad Sci U S A 85: 1033–1037.
31. YousefMR, GrundyFJ, HenkinTM (2003) tRNA requirements for glyQS antitermination: a new twist on tRNA. RNA 9: 1148–1156.
Štítky
Hygiena a epidemiológia Infekčné lekárstvo LaboratóriumČlánok vyšiel v časopise
PLOS Pathogens
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