Vladimirov S N, Graĭfer D M, Zenkova M A, Kazakov S A, Karpova G G
Bioorg Khim. 1987 Aug;13(8):1053-8.
The use of some bifunctional Pt(II)-containing cross-linking reagents for investigation of structural organization of ribosomal tRNA- and mRNA-binding centres is demonstrated for various types of [70S ribosome.mRNA-tRNA] complexes. It is shown that treatment of the complexes [70S ribosome.Ac[14C]Phe-tRNA(Phe).poly(U)], [70S ribosome.3'-32pCp-tRNA(Phe).poly(U)] and [70S ribosome.f[35S]Met-tRNA(fMet).AUGU6] with Pt(II)-derivatives results in covalent attachment of tRNA to ribosome. AcPhe-tRNA(Phe) and 3'-pCp-tRNA(Phe) bound at the P site were found to be cross-linked preferentially to 30S subunit. fMet-tRNA(fMet) within the 70S initiation complex is cross-linked to both ribosome subunits approximately in the same extent, which exceeds two-fold the level of the tRNA(Phe) cross-linking. All used tRNA species were cross-linked in the comparable degree both to rRNA and proteins of both subunits in all types of the complexes studied. 32pAUGU6 cross-links exclusively to 30S subunit (to 16S RNA only) within [70S ribosome.32pAUGU6.fMet-tRNA(fMet)] complex. In the absence of fMet-tRNAfMet the level of the cross-linking is 4-fold lower.
对于各种类型的[70S核糖体.mRNA - tRNA]复合物，展示了使用一些含双功能Pt(II)的交联试剂来研究核糖体tRNA和mRNA结合中心的结构组织。结果表明，用Pt(II)衍生物处理复合物[70S核糖体.Ac[14C]苯丙氨酸 - tRNA(苯丙氨酸).聚(U)]、[70S核糖体.3'-32pCp - tRNA(苯丙氨酸).聚(U)]和[70S核糖体.f[35S]甲硫氨酸 - tRNA(fMet).AUGU6]会导致tRNA与核糖体的共价连接。发现结合在P位点的Ac苯丙氨酸 - tRNA(苯丙氨酸)和3'-pCp - tRNA(苯丙氨酸)优先与30S亚基交联。70S起始复合物中的fMet - tRNA(fMet)与两个核糖体亚基的交联程度大致相同，这比tRNA(苯丙氨酸)的交联水平高出两倍多。在所有研究的复合物类型中，所有使用的tRNA种类与两个亚基的rRNA和蛋白质的交联程度相当。在[70S核糖体.32pAUGU6.fMet - tRNA(fMet)]复合物中，32pAUGU6仅与30S亚基（仅与16S RNA）交联。在没有fMet - tRNAfMet的情况下，交联水平降低4倍。
