TY - JOUR
T1 - An RNA Binding Site in a tRNA Synthetase with a Reduced Set of Amino Acids
AU - Kim, Sunghoon
AU - de Pouplana, Lluis Ribas
AU - Schimmel, Paul
PY - 1994/9/1
Y1 - 1994/9/1
N2 - A 30 amino acid helix-loop of known structure on the surface of the C-terminal domain of the class I Escherichia coli methionine tRNA synthetase is essential for methionine tRNA anticodon discrimination. Replacing this 30 amino acid peptide with a previously described sequence containing residues from the wild-type protein imbedded in a sequence matrix of mostly alanines and serines, we used a combinatorial mutagenesis and selection strategy to define residual wild-type residues that are not replaceable with alanine or serine, because they are needed for specific recognition of methionine tRNA. Four were identified, of which three have functional side chains (Asn, Arg, Lys). These four and a fifth (Trp) that was previously identified are located at the end of the helix and within the loop, lie on the same side of the structure, and span a distance of about 20 Å. We conclude that, within the alanine, serine sequence matrix, only a few non-alanine, non-serine residues in the specificity-determining part of the structure are essential.
AB - A 30 amino acid helix-loop of known structure on the surface of the C-terminal domain of the class I Escherichia coli methionine tRNA synthetase is essential for methionine tRNA anticodon discrimination. Replacing this 30 amino acid peptide with a previously described sequence containing residues from the wild-type protein imbedded in a sequence matrix of mostly alanines and serines, we used a combinatorial mutagenesis and selection strategy to define residual wild-type residues that are not replaceable with alanine or serine, because they are needed for specific recognition of methionine tRNA. Four were identified, of which three have functional side chains (Asn, Arg, Lys). These four and a fifth (Trp) that was previously identified are located at the end of the helix and within the loop, lie on the same side of the structure, and span a distance of about 20 Å. We conclude that, within the alanine, serine sequence matrix, only a few non-alanine, non-serine residues in the specificity-determining part of the structure are essential.
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U2 - 10.1021/bi00202a025
DO - 10.1021/bi00202a025
M3 - Article
C2 - 7522052
AN - SCOPUS:0028000616
VL - 33
SP - 11040
EP - 11045
JO - Biochemistry
JF - Biochemistry
SN - 0006-2960
IS - 36
ER -