Structure of a mimic of aminoacylated tRNA determined by means of transferred NOE data

✍ Scribed by Martin Vogtherr; Stefan Limmer

• Publisher: John Wiley and Sons
• Year: 1998
• Tongue: English
• Weight: 109 KB
• Volume: 36
• Category: Article
• ISSN: 0749-1581
• DOI: 10.1002/(sici)1097-458x(199812)36:12<901::aid-omr385>3.0.co;2-l

✦ Synopsis

Anthraniloyladenosine (Ant-Ado) serves as an analog for aminoacylated tRNA and is speciÐcally recognized by bacterial elongation factor Tu (EF-Tu). In this compound, adenosine is esteriÐed with anthranilic acid, which mimics an a-amino acid. The weak binding of Ant-Ado to the EF-Tu gives rise to transfer-NOE (TrNOE) signals from which the conformation of Ant-Ado in its protein-bound state can be deduced. To this end a full relaxation matrix approach was used with the R-factor as a target function. The position of the base was determined by a mapping procedure. Structures of ribose and anthranilic acid were obtained by simulated annealing. The nucleotide was found to be in 2@-endo puckering, with the base in an anti conformation. The anthranilic acid adopts a position in which an amino group is presented in a similar way as by phenylalanine in the crystal structure of the ternary complex EF-Tu É GPPNHP É Phe-tRNAPhe.