Reductive cleavage of S-adenosylmethionine by biotin synthase from Escherichia coli
Ollagnier-de Choudens, Sandrine, Sanakis, Yiannis, Hewitson, Kirsty S., Roach, Peter, Münck, Eckard and Fontecave, Marc (2002) Reductive cleavage of S-adenosylmethionine by biotin synthase from Escherichia coli. Journal of Biological Chemistry, 277, (16), 13449-13454. (doi:10.1074/jbc.M111324200).
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Description/Abstract
Biotin synthase (BioB) catalyzes the insertion of a sulfur atom between the C6 and C9 carbons of dethiobiotin. Reconstituted BioB from Escherichia coli contains a [4Fe-4S](2+/1+) cluster thought to be involved in the reduction and cleavage of S-adenosylmethionine (AdoMet), generating methionine and the reactive 5'-deoxyadenosyl radical responsible for dethiobiotin H-abstraction. Using EPR and Mössbauer spectroscopy as well as methionine quantitation we demonstrate that the reduced S = 1/2 [4Fe-4S](1+) cluster is indeed capable of injecting one electron into AdoMet, generating one equivalent of both methionine and S = 0 [4Fe-4S](2+) cluster. Dethiobiotin is not required for the reaction. Using site-directed mutagenesis we show also that, among the eight cysteines of BioB, only three (Cys-53, Cys-57, Cys-60) are essential for AdoMet reductive cleavage, suggesting that these cysteines are involved in chelation of the [4Fe-4S](2+/1+) cluster.
| Item Type: | Article |
|---|---|
| ISSNs: | 0021-9258 (print) |
| Related URLs: | |
| Keywords: | iron-sulfur cluster, pyruvate formate-lyase, anaerobic ribonucleotide reductase, electron-paramagnetic-resonance, lysine 2,3-aminomutase, radical mechanisms, activating enzyme, single turnover, in-vitro, protein |
| Subjects: | Q Science > QD Chemistry Q Science > QR Microbiology |
| Divisions: | University Structure - Pre August 2011 > School of Chemistry |
| Item ID: | 19832 |
| Date Deposited: | 22 Feb 2006 |
| Last Modified: | 01 Jun 2011 06:14 |
| Contributors: | Ollagnier-de Choudens, Sandrine (Author) Sanakis, Yiannis (Author) Hewitson, Kirsty S. (Author) Roach, Peter (Author) Münck, Eckard (Author) Fontecave, Marc (Author) |
| Date: | 19 April 2002 |
| Status: | Published |
| URI: | http://eprints.soton.ac.uk/id/eprint/19832 |
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