Identification of a histidine residue near the aminoacyl transfer ribonucleic acid binding site of elongation factor Tu.
The complex of elongation factor Tu with GTP (EF-Tu.GTP) reacts with N or epsilon -bromoacetyl-lys-tRNA ( or epsilon BrAcLys-tRNA) to form a functional covalently linked complex (XLTC). The site of cross-linking must be near the site on EF-Tu.GTP that binds the aminoacyl moiety of aminoacyl transfer ribonucleic acid (AA-tRNA). For identification of this site, a nanomole of purified XLTC prepared from or epsilon BrAc[(14)C]Lys-tRNA was digested first with RNase A and then with trypsin, and the peptides were resolved by high-performance liquid chromatography using a c8 reverse-phase column. A single peptide contained 80% of the label. The amino acid composition of this peptide was identical with that of residues 59-74 in EF-Tu. The NH2-terminal sequence of the peptide was determined to be Fly-Ile-Thr-Ile, which are residues 59-62 in EF-Tu. The modified amino acid was identified as pi - (carboxymethyl)histidine, which establishes that His-66 is at or near the AA-tRNA binding site on EF-Tu.GTP.
D000345:Affinity Labels / Q000378:metabolism; D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000378:metabolism*; D001665:Binding Sites; D006160:Guanosine Triphosphate / Q000378:metabolism; D006639:Histidine; D006863:Hydrogen-Ion Concentration; D010444:Peptide Elongation Factor Tu; D010445:Peptide Elongation Factors / Q000378:metabolism*; D011485:Protein Binding; D012346:RNA, Transfer, Amino Acyl / Q000378:metabolism*
D000345:Affinity Labels; D001426:Bacterial Proteins; D010445:Peptide Elongation Factors; D012346:RNA, Transfer, Amino Acyl; C027354:tRNA, N-epsilon-bromoacetyllysine-; D006639:Histidine; D006160:Guanosine Triphosphate; D010444:Peptide Elongation Factor Tu