A recurrent RNA-binding domain is appended to eukaryotic aminoacyl-tRNA synthetases.
Aminoacyl-tRNA synthetases of higher eukaryotes possess polypeptide extensions in contrast to their prokaryotic counterparts. These extra domains of poorly understood function are believed to be involved in protein-protein or protein-RNA interactions. Here we showed by gel retardation and filter binding experiments that the repeated units that build the linker region of the bifunctional glutamyl-prolyl-tRNA synthetase had a general RNA-binding capacity. The solution structure of one of these repeated motifs was also solved by NMR spectroscopy. One repeat is built around an antiparallel coiled-coil. Strikingly, the conserved lysine and arginine residues form a basic patch on one side of the structure, presenting a suitable docking surface for nucleic acids. Therefore, this repeated motif may represent a novel type of general RNA-binding domain appended to eukaryotic aminoacyl-tRNA synthetases to serve as a cis-acting tRNA-binding cofactor.
Cahuzac
B
B
Laboratoire de RMN, ICSN-CNRS, Gif-sur-Yvette, France.
Berthonneau
E
E
Birlirakis
N
N
Guittet
E
E
Mirande
M
M
D000595:Amino Acid Sequence; D000604:Amino Acyl-tRNA Synthetases / Q000737:chemistry*; D000818:Animals; D001665:Binding Sites; D017124:Conserved Sequence; D006224:Cricetinae; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D008969:Molecular Sequence Data; D011068:Poly G / Q000378:metabolism; D016601:RNA-Binding Proteins / Q000737:chemistry*; D020449:Repetitive Sequences, Amino Acid; D016415:Sequence Alignment
D016601:RNA-Binding Proteins; D011068:Poly G; D000604:Amino Acyl-tRNA Synthetases