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Evidence for a polynuclear metal ion binding site in the catalytic domain of ribonuclease P RNA
Author(s) -
Christian Eric L.,
Kaye Nicholas M.,
Harris Michael E.
Publication year - 2002
Publication title -
the embo journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 7.484
H-Index - 392
eISSN - 1460-2075
pISSN - 0261-4189
DOI - 10.1093/emboj/21.9.2253
Subject(s) - ribozyme , rnase p , rna , ribonuclease , rnase h , chemistry , nucleotide , nucleobase , metal , base pair , nucleic acid structure , vs ribozyme , ligase ribozyme , crystallography , stereochemistry , biochemistry , dna , gene , organic chemistry
Interactions with divalent metal ions are essential for the folding and function of the catalytic RNA component of the tRNA processing enzyme ribonuclease P (RNase P RNA). However, the number and location of specific metal ion interactions in this large, highly structured RNA are poorly understood. Using atomic mutagenesis and quantitative analysis of thiophilic metal ion rescue we provide evidence for metal ion interactions at the pro ‐R P and pro ‐S P non‐bridging phosphate oxygens at nucleotide A67 in the universally conserved helix P4. Moreover, second‐site modifications within helix P4 and the adjacent single stranded region (J3/4) provide the first evidence for metal ion interactions with nucleotide base functional groups in RNase P RNA and reveal the presence of an additional metal ion important for catalytic function. Together, these data are consistent with a cluster of metal ion interactions in the P1–P4 multi‐helix junction that defines the catalytic core of the RNase P ribozyme.