Ribas de Pouplana L, Buechter D, Sardesai N Y, Schimmel P
The Skaggs Institute for Chemical Biology and Departments of Molecular Biology and Chemistry, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA.
EMBO J. 1998 Sep 15;17(18):5449-57. doi: 10.1093/emboj/17.18.5449.
RNA microhelices that recreate the acceptor stems of transfer RNAs are charged with specific amino acids. Here we identify a two-helix pair in alanyl-tRNA synthetase that is required for RNA microhelix binding. A single point mutation at an absolutely conserved residue in this motif selectively disrupts RNA binding without perturbation of the catalytic site. These results, and findings of similar motifs in the proximity of the active sites of other tRNA synthetases, suggest that two-helix pairs are widespread and provide a structural framework important for contacts with bound RNA substrates.
能够重现转运RNA受体茎的RNA微螺旋被特定氨基酸负载。我们在此鉴定出丙氨酰-tRNA合成酶中一个RNA微螺旋结合所需的双螺旋对。该基序中一个绝对保守残基处的单点突变选择性地破坏RNA结合,而不干扰催化位点。这些结果,以及在其他tRNA合成酶活性位点附近发现的类似基序,表明双螺旋对广泛存在,并为与结合的RNA底物的接触提供了重要的结构框架。