The beta subunit of E. coli glycyl-tRNA synthetase plays a major role in tRNA recognition.

AUTOR(ES)

Nagel, G M

RESUMO

The contributions made by the alpha and beta subunits of E. coli glycyl-tRNA synthetase to the recognition of tRNA have been investigated via binding and immunological methods. Using the nitrocellulose filter assay, we have shown that isolated beta subunit, but not the alpha subunit, binds [14C]glycyl-tRNA with an affinity comparable to that of the native enzyme. Further, the data indicate that the beta subunit possesses one binding site for glycyl-tRNA while the native or reconstituted enzyme (alpha 2 beta 2) has two sites. Rabbit antibodies directed at the beta subunit or the holoenzyme inhibit efficiently the ability of the enzyme to aminoacylate tRNA while alpha-subunit antibodies have a smaller effect. Since none of the antisera have an appreciable effect on the ATP-PPi exchange activity of the enzyme under these conditions, the beta-subunit (and holoenzyme) antisera evidently interfere with productive tRNA binding. Taken together, the data indicate that the larger, beta subunit of glycyl-tRNA synthetase plays a major role in tRNA recognition.

Documentos Relacionados

• The glycyl-tRNA synthetase of Chlamydia trachomatis.
• Crystal structure of glycyl-tRNA synthetase from Thermus thermophilus.
• Glycyl-tRNA Synthetase: An Oligomeric Protein Containing Dissimilar Subunits*
• Inactivation of a glycyl-tRNA synthetase leads to an arrest in plant embryo development.
• Crystal Structures and Biochemical Analyses Suggest a Unique Mechanism and Role for Human Glycyl-tRNA Synthetase in Ap4A Homeostasis*