Department of Biology and Biochemistry, University of Houston, Houston, Texas 77204, USA.
Protein Sci. 2012 Nov;21(11):1696-704. doi: 10.1002/pro.2149. Epub 2012 Sep 25.
The ribosome is a ribozyme. However, in bacterial ribosomes, the N-terminus of L27 is located within the peptidyl transfer center. The roles of this protein in real time remain unclear. We present single-molecule fluorescence resonance energy transfer (FRET) studies of tRNA dynamics at the peptidyl transfer center in ribosomes containing either wild type (WT) L27, or L27 mutants with A2H3, A2H3K4 or nine N-terminal residues removed. Removing L27's first three N-terminal residues or mutating a single residue, K4, reduces the formation of a stable peptidyl tRNA after translocation. These results imply that L27 stabilizes the peptidyl tRNA and residue K4 contributes significantly to the stabilization.
核糖体是核酶。然而,在细菌核糖体中,L27 的 N 端位于肽转移中心内。该蛋白在实时状态下的作用尚不清楚。我们进行了单分子荧光共振能量转移(FRET)研究,以研究在含有野生型(WT)L27 或具有 A2H3、A2H3K4 或九个 N 端残基缺失的 L27 突变体的核糖体中,肽转移中心处 tRNA 的动力学。去除 L27 的前三个 N 端残基或突变单个残基 K4 会减少转位后稳定肽基 tRNA 的形成。这些结果表明,L27 稳定了肽基 tRNA,残基 K4 对其稳定性有重要贡献。