TY - JOUR
T1 - Helix 69 is key for uniformity during substrate selection on the ribosome
AU - Ortiz-Meoz, Rodrigo F.
AU - Green, Rachel
PY - 2011/7/22
Y1 - 2011/7/22
N2 - Structural studies of ribosome complexes with bound tRNAs and release factors show considerable contacts between these factors and helix 69 (H69) of 23 S rRNA. Although biochemical and genetic studies have provided some general insights into the role of H69 in tRNA and RF selection, a detailed understanding of these contributions remains elusive. Here, we present a pre-steady-state kinetic analysis establishing that two distinct regions of H69 make critical contributions to substrate selection. The loop of H69 (A1913) forms contacts necessary for the efficient accommodation of a subset of natural tRNA species, whereas the base of the stem (G1922) is specifically critical for UGA codon recognition by the class 1 release factor RF2. These data define a broad and critical role for this centrally located intersubunit helix (H69) in accurate and efficient substrate recognition by the ribosome.
AB - Structural studies of ribosome complexes with bound tRNAs and release factors show considerable contacts between these factors and helix 69 (H69) of 23 S rRNA. Although biochemical and genetic studies have provided some general insights into the role of H69 in tRNA and RF selection, a detailed understanding of these contributions remains elusive. Here, we present a pre-steady-state kinetic analysis establishing that two distinct regions of H69 make critical contributions to substrate selection. The loop of H69 (A1913) forms contacts necessary for the efficient accommodation of a subset of natural tRNA species, whereas the base of the stem (G1922) is specifically critical for UGA codon recognition by the class 1 release factor RF2. These data define a broad and critical role for this centrally located intersubunit helix (H69) in accurate and efficient substrate recognition by the ribosome.
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U2 - 10.1074/jbc.M111.256255
DO - 10.1074/jbc.M111.256255
M3 - Article
C2 - 21622559
AN - SCOPUS:79960396249
SN - 0021-9258
VL - 286
SP - 25604
EP - 25610
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
IS - 29
ER -