Alessio BocediRaffaele FabriniAndrea FarrottiLorenzo StellaAlbert J. KettermanJens Z. PedersenNerino AllocatiPeter C.K. LauStephan GrosseLindsay D. EltisAntonio RuzziniThomas E. EdwardsLaura MoriciErica Del GrossoLeonardo GuidoniDaniele BoviMario Lo BelloGiorgio FedericiMichael W. ParkerPhilip G. BoardGiorgio RicciDepartment of Chemical Sciences and TechnologiesMahidol UniversityUniversita degli Studi di Roma La SapienzaUniversity of G. d'Annunzio Chieti and PescaraMcGill UniversityThe University of British ColumbiaSeattle Structural Genomics Center for Infectious DiseaseEmerald BioStructures Inc.Universita degli Studi dell'AquilaIRCCS Ospedale Pediatrico Bambino GesuSt Vincent's InstituteBio21 Molecular Science and Biotechnology InstituteAustralian National University2018-10-192018-10-192013-08-23Journal of Biological Chemistry. Vol.288, No.34 (2013), 24936-249471083351X002192582-s2.0-84883184902https://repository.li.mahidol.ac.th/handle/20.500.14594/31240Background: Why do ancestral GSTs utilize cysteine/serine as catalytic residues, whereas more recently evolved GSTs utilize tyrosine? Results: Only the more recently evolved GSTs display enough affinity to bind and make harmless the toxic DNDGIC (a natural NO carrier). Conclusion: GST evolution could be linked to the defense against NO. Significance: This represents a further piece in the puzzle of evolutive adaptation to NO toxicity. Glutathione transferases (GSTs) are protection enzymes capable of conjugating glutathione (GSH) to toxic compounds. During evolution an important catalytic cysteine residue involved in GSH activation was replaced by serine or, more recently, by tyrosine. The utility of these replacements represents an enigma because they yield no improvements in the affinity toward GSH or in its reactivity. Here we show that these changes better protect the cell from nitric oxide (NO) insults. In fact the dinitrosyl-diglutathionyl-iron complex (DNDGIC), which is formed spontaneously when NO enters the cell, is highly toxic when free in solution but completely harmless when bound to GSTs. By examining 42 different GSTs we discovered that only the more recently evolved Tyr-based GSTs display enough affinity for DNDGIC (KD < 10-9 M) to sequester the complex efficiently. Ser-based GSTs and Cys-based GSTs show affinities 10 2-104 times lower, not sufficient for this purpose. The NO sensitivity of bacteria that express only Cys-based GSTs could be related to the low or null affinity of their GSTs for DNDGIC. GSTs with the highest affinity (Tyr-based GSTs) are also over-represented in the perinuclear region of mammalian cells, possibly for nucleus protection. On the basis of these results we propose that GST evolution in higher organisms could be linked to the defense against NO. © 2013 by The American Society for Biochemistry and Molecular Biology, Inc.Mahidol UniversityBiochemistry, Genetics and Molecular BiologyArticleSCOPUS10.1074/jbc.M113.476135