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Riboswitch (T-box)-mediated control of tRNA-dependent amidation in Clostridium acetobutylicum rationalizes gene and pathway redundancy for asparagine and asparaginyl-trnaasn synthesis.

Riboswitch (T-box)-mediated control of tRNA-dependent amidation in Clostridium acetobutylicum rationalizes gene and pathway redundancy for asparagine and asparaginyl-trnaasn synthesis.

Authors :
Saad NY
Schiel B
Brayé M
Heap JT
Minton NP
Dürre P
Becker HD
Source :
The Journal of biological chemistry [J Biol Chem] 2012 Jun 08; Vol. 287 (24), pp. 20382-94. Date of Electronic Publication: 2012 Apr 13.
Publication Year :
2012

Abstract

Analysis of the Gram-positive Clostridium acetobutylicum genome reveals an inexplicable level of redundancy for the genes putatively involved in asparagine (Asn) and Asn-tRNA(Asn) synthesis. Besides a duplicated set of gatCAB tRNA-dependent amidotransferase genes, there is a triplication of aspartyl-tRNA synthetase genes and a duplication of asparagine synthetase B genes. This genomic landscape leads to the suspicion of the incoherent simultaneous use of the direct and indirect pathways of Asn and Asn-tRNA(Asn) formation. Through a combination of biochemical and genetic approaches, we show that C. acetobutylicum forms Asn and Asn-tRNA(Asn) by tRNA-dependent amidation. We demonstrate that an entire transamidation pathway composed of aspartyl-tRNA synthetase and one set of GatCAB genes is organized as an operon under the control of a tRNA(Asn)-dependent T-box riboswitch. Finally, our results suggest that this exceptional gene redundancy might be interconnected to control tRNA-dependent Asn synthesis, which in turn might be involved in controlling the metabolic switch from acidogenesis to solventogenesis in C. acetobutylicum.

Details

Language :
English
ISSN :
1083-351X
Volume :
287
Issue :
24
Database :
MEDLINE
Journal :
The Journal of biological chemistry
Publication Type :
Academic Journal
Accession number :
22505715
Full Text :
https://doi.org/10.1074/jbc.M111.332304