3KFU

Crystal structure of the transamidosome

Summary for 3KFU

• Entry DOI: 10.2210/pdb3kfu/pdb
• Descriptor: Non-discriminating and archaeal-type aspartyl-tRNA synthetase, Glutamyl-tRNA(Gln) amidotransferase subunit A, Aspartyl/glutamyl-tRNA(Asn/Gln) amidotransferase subunit B, ... (8 entities in total)
• Functional Keywords: asprs, gatcab, atp-binding, aminoacyl-trna synthetase, ligase, nucleotide-binding, protein biosynthesis, ligase-rna complex, ligase/rna
• Biological source: Thermus thermophilus; More
• Total number of polymer chains: 14
• Total formula weight: 514210.28

Authors

Blaise, M.,Bailly, M.,Frechin, M.,Thirup, S.,Becker, H.D.,Kern, D. (deposition date: 2009-10-28, release date: 2010-08-25, Last modification date: 2023-09-06)

Primary citation

Blaise, M.,Bailly, M.,Frechin, M.,Behrens, M.A.,Fischer, F.,Oliveira, C.L.,Becker, H.D.,Pedersen, J.S.,Thirup, S.,Kern, D.
Crystal structure of a transfer-ribonucleoprotein particle that promotes asparagine formation.
Embo J., 29:3118-3129, 2010

PubMed Abstract: Four out of the 22 aminoacyl-tRNAs (aa-tRNAs) are systematically or alternatively synthesized by an indirect, two-step route requiring an initial mischarging of the tRNA followed by tRNA-dependent conversion of the non-cognate amino acid. During tRNA-dependent asparagine formation, tRNA(Asn) promotes assembly of a ribonucleoprotein particle called transamidosome that allows channelling of the aa-tRNA from non-discriminating aspartyl-tRNA synthetase active site to the GatCAB amidotransferase site. The crystal structure of the Thermus thermophilus transamidosome determined at 3 A resolution reveals a particle formed by two GatCABs, two dimeric ND-AspRSs and four tRNAs(Asn) molecules. In the complex, only two tRNAs are bound in a functional state, whereas the two other ones act as an RNA scaffold enabling release of the asparaginyl-tRNA(Asn) without dissociation of the complex. We propose that the crystal structure represents a transient state of the transamidation reaction. The transamidosome constitutes a transfer-ribonucleoprotein particle in which tRNAs serve the function of both substrate and structural foundation for a large molecular machine.

PubMed: 20717102
DOI: 10.1038/emboj.2010.192

Experimental method

X-RAY DIFFRACTION (3 Å)