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PubMed · 3844012

Cooperativity in low-affinity Mg2+ binding to tRNA.

D Labuda·K Nicoghosian·R Cedergren
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Abstract

The Pb2+-catalyzed cleavage of tRNAPhe has been used to probe the effect of Na+ and Mg2+ binding to tRNA. Na+ is a noncompetitive inhibitor of the Pb2+-catalyzed cleavage. Millimolar Mg2+ is also a noncompetitive inhibitor. Analysis of the Mg2+ data show that at least two sites are involved in binding and that there is an interaction between the sites (cooperativity). Low-affinity Mg2+ binding is thus different from "weak" and "strong" Mg2+ binding to tRNA characterized previously. We postulate that the alterations induced by low-affinity Mg2+ binding in tRNA mimic to some extent those brought about in RNA by the interaction with a protein factor and that at appropriate [Mg2+] the whole structure of tRNA is able to respond in a concerted way to a signal from the environment such as aminoacylation or codon binding.

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Binding SitesCrystallographyHydrolysisLeadMagnesiumMathematicsRNA, TransferRNA, Transfer, Amino AcylSodiumYeastsJournal ArticleResearch Support, Non-U.S. Gov't

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D Labuda, K Nicoghosian, R Cedergren. 1985-01-25. Cooperativity in low-affinity Mg2+ binding to tRNA.. https://pubmed.ncbi.nlm.nih.gov/3844012/

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