Skip to Main content Skip to Navigation
Theses

Insertion de soufre en biologie par voie radicalaire. Etude des méthylthiotransférases

Abstract : One of the chemically most challenging problems in enzymology is the functionalization of non-reactive C–H bonds. Such reactions require specialized cofactors as heme, Fe-µ-oxo or vitamin B12. In 2001, special Fe-S centers able to bind S-Adenosylmethionine (SAM) have been shown to activate non-reactive C-H bonds toward subsequent functionalization. Enzymes containing this new cofactor constitute a super-family called “Radical SAM”. Methylthiotransferases (MTTases) belong to the “Radical SAM” super-family and catalyse the insertion of a methylthio group (-SCH3) in C-H bonds. By doing in vitro and in vivo experiments, we were able to classify them into three groups. The first class, (RimO) catalyses the formation of β-methylthio-aspartate 89 on the ribosomal protein S12 (β-ms-D89-S12) whereas the two others (MiaB and MtaB/eMtaB) respectively catalyse the thiomethylation of the nucleosides 2-methylthio-N6-isopentenyladenosine 37 (ms2i6A-37) and 2-methylthio-N6-threoninecarbamoyl adenosine 37 (ms2t6A-37) present in some tRNA. Our studies have shown that, in vitro, MTTases catalyse the insertion of a SCH3 group in a catalytic way suggesting entirely new radical sulfur insertion mechanisms.
Document type :
Theses
Complete list of metadata

Cited literature [70 references]  Display  Hide  Download

https://tel.archives-ouvertes.fr/tel-00820033
Contributor : ABES STAR :  Contact
Submitted on : Friday, May 3, 2013 - 1:02:20 AM
Last modification on : Friday, March 25, 2022 - 9:43:30 AM
Long-term archiving on: : Sunday, August 4, 2013 - 4:03:09 AM

File

ThA_se_-_Simon_-_Arragain_-_De...
Version validated by the jury (STAR)

Identifiers

  • HAL Id : tel-00820033, version 1

Collections

Citation

Simon Arragain. Insertion de soufre en biologie par voie radicalaire. Etude des méthylthiotransférases. Autre [q-bio.OT]. Université de Grenoble, 2011. Français. ⟨NNT : 2011GRENV048⟩. ⟨tel-00820033⟩

Share

Metrics

Record views

267

Files downloads

298