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Thermodynamic Analysis of Leadzyme
Author(s) -
Thall Brittney Dianne,
Grover Neena
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.21.6.a1027-b
The folding and catalysis of small RNA enzymes requires metal ion cofactors. The lead‐dependent ribozyme (leadzyme) is a twelve‐nucleotide RNA with a six‐nucleotide active site, of which bases C6, G9, and G24 are conserved. Biochemical studies show that A25 is important for the structure formation but is not conserved; the protonation of A25 (pKa=6.5) allows it to form an A + ·C base pair. Also, lead binds to the N7 and O6 on G9. In this study, the role of non‐canonical base pairs and metal ion binding is being investigated by thermal denaturation experiments. To examine the contribution of A + ·C base pair, RNA thermodynamics were measured under pH 5.5 and 7.5 conditions. Contributions of non‐canonical bonding to RNA stability were examined by studying C6A, G9A, and G24A modifications. The contribution of divalent ions to leadzyme stability was determined by comparative thermodynamic analysis in 1M salt and in various Mg 2+ ion concentrations.