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Thermodynamic Examination of Leadzyme
Author(s) -
Frost Arian Cai,
Grover Neena
Publication year - 2011
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.25.1_supplement.903.1
Subject(s) - chemistry , hydrogen bond , crystallography , ribozyme , rna , base pair , ionic strength , thermal stability , ionic bonding , ion , stereochemistry , molecule , dna , biochemistry , organic chemistry , aqueous solution , gene
The leadzyme is a small, double‐stranded, artificially created ribozyme that contains an asymmetrical 4×2 bulge. This bulge region contains four unpaired bases and at least one non‐canonical base pair. The bulge cleaves in the presence of lead and can be competed out by Mg2+. The leadzyme contains three conserved bases (C6, G9, and G24) that are implicated in divalent metal ion binding and structure stabilization. NMR data suggests the formation of an A25+‐C6 non‐canonical base pair with two hydrogen bonds while the crystal structure of the leadzyme shows one hydrogen bond. The active site bulge in the leadzyme may be flexible under different ionic conditions and pH environments. Thermal denaturation experiments were used to compare the relative stability of the wild type RNA in the presence of various concentrations of Mg2+ ions in pH 5.5 and 7.5. Our data shows that the second hydrogen bond between A25‐C6 is not forming. The ion binding properties of the leadzyme are being examined in RNA constructs where the conserved sites have been modified. Results of leadzyme stability and ion binding properties will be presented.