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TtcA a new tRNA-thioltransferase with an Fe-S cluster.

ABSTRACT: TtcA catalyzes the post-transcriptional thiolation of cytosine 32 in some tRNAs. The enzyme from Escherichia coli was homologously overexpressed in E. coli. The purified enzyme is a dimer containing an iron-sulfur cluster and displays activity in in vitro assays. The type and properties of the cluster were investigated using a combination of UV-visible absorption, EPR and Mössbauer spectroscopy, as well as by site-directed mutagenesis. These studies demonstrated that the TtcA enzyme contains a redox-active and oxygen-sensitive [4Fe-4S] cluster, chelated by only three cysteine residues and absolutely essential for activity. TtcA is unique tRNA-thiolating enzyme using an iron-sulfur cluster for catalyzing a non-redox reaction.

SUBMITTER: Bouvier D

PROVIDER: S-EPMC4081106 | biostudies-literature | 2014 Jul

REPOSITORIES: biostudies-literature

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TtcA a new tRNA-thioltransferase with an Fe-S cluster.

Bouvier Denis D Labessan Natty N Clémancey Martin M Latour Jean-Marc JM Ravanat Jean-Luc JL Fontecave Marc M Atta Mohamed M

Nucleic acids research 20140609 12

TtcA catalyzes the post-transcriptional thiolation of cytosine 32 in some tRNAs. The enzyme from Escherichia coli was homologously overexpressed in E. coli. The purified enzyme is a dimer containing an iron-sulfur cluster and displays activity in in vitro assays. The type and properties of the cluster were investigated using a combination of UV-visible absorption, EPR and Mössbauer spectroscopy, as well as by site-directed mutagenesis. These studies demonstrated that the TtcA enzyme contains a r ...[more]

PMID: 24914049

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