1Y42

Crystal structure of a C-terminally truncated CYT-18 protein

Summary for 1Y42

• Entry DOI: 10.2210/pdb1y42/pdb
• Descriptor: Tyrosyl-tRNA synthetase, mitochondrial, TYROSINE (3 entities in total)
• Functional Keywords: cyt-18, tyrosyl trna synthetase, trna ligase, group i intron, ligase
• Biological source: Neurospora crassa
• Cellular location: Mitochondrion matrix: P12063
• Total number of polymer chains: 1
• Total formula weight: 45103.32

Authors

Paukstelis, P.J.,Coon, R.,Madabusi, L.,Nowakowski, J.,Monzingo, A.,Robertus, J.,Lambowitz, A.M. (deposition date: 2004-11-29, release date: 2005-02-15, Last modification date: 2023-08-23)

Primary citation

Paukstelis, P.J.,Coon, R.,Madabusi, L.,Nowakowski, J.,Monzingo, A.,Robertus, J.,Lambowitz, A.M.
A tyrosyl-tRNA synthetase adapted to function in group I intron splicing by acquiring a new RNA binding surface.
Mol.Cell, 17:417-428, 2005

PubMed Abstract: We determined a 1.95 A X-ray crystal structure of a C-terminally truncated Neurospora crassa mitochondrial tyrosyl-tRNA synthetase (CYT-18 protein) that functions in splicing group I introns. CYT-18's nucleotide binding fold and intermediate alpha-helical domains superimpose on those of bacterial TyrRSs, except for an N-terminal extension and two small insertions not found in nonsplicing bacterial enzymes. These additions surround the cyt-18-1 mutation site and are sites of suppressor mutations that restore splicing, but not synthetase activity. Highly constrained models based on directed hydroxyl radical cleavage assays show that the group I intron binds at a site formed in part by the three additions on the nucleotide binding fold surface opposite that which binds tRNATyr. Our results show how essential proteins can progressively evolve new functions.

PubMed: 15694342
DOI: 10.1016/j.molcel.2004.12.026

Experimental method

X-RAY DIFFRACTION (1.95 Å)