Abstract
The antimicrobial agent pentamidine inhibits the self-splicing of the group I intron Ca.LSU from the transcripts of the 26S rRNA gene of Candida albicans, but the mechanism of pentamidine inhibition is not clear. We show that preincubation of the ribozyme with pentamidine enhances the inhibitory effect of the drug and alters the folding of the ribozyme in a pattern varying with drug concentration. Pentamidine at 25 μM prevents formation of the catalytically active F band conformation of the precursor RNA and alters the ribonuclease T1 cleavage pattern of Ca.LSU RNA. The effects on cleavage suggest that pentamidine mainly binds to specific sites in or near asymmetric loops of helices P2 and P2.1 on the ribozyme, as well as to the tetraloop of P9.2 and the loosely paired helix P9, resulting in an altered structure of helix P7, which contains the active site. Positively charged molecules antagonize pentamidine inhibition of catalysis and relieve the drug effect on ribozyme folding, suggesting that pentamidine binds to a magnesium binding site(s) of the ribozyme to exert its inhibitory effect.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 2961-2971 |
| Number of pages | 11 |
| Journal | Nucleic Acids Research |
| Volume | 30 |
| Issue number | 13 |
| State | Published - Jul 1 2002 |
| Externally published | Yes |
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Cite this
Pentamidine inhibits catalytic activity of group I intron Ca.LSU by altering RNA folding. / Zhang, Yi; Li, Zhijie; Pilch, Daniel S.; Leibowitz, Michael J.
In: Nucleic Acids Research, Vol. 30, No. 13, 01.07.2002, p. 2961-2971.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Pentamidine inhibits catalytic activity of group I intron Ca.LSU by altering RNA folding
AU - Zhang, Yi
AU - Li, Zhijie
AU - Pilch, Daniel S.
AU - Leibowitz, Michael J
PY - 2002/7/1
Y1 - 2002/7/1
N2 - The antimicrobial agent pentamidine inhibits the self-splicing of the group I intron Ca.LSU from the transcripts of the 26S rRNA gene of Candida albicans, but the mechanism of pentamidine inhibition is not clear. We show that preincubation of the ribozyme with pentamidine enhances the inhibitory effect of the drug and alters the folding of the ribozyme in a pattern varying with drug concentration. Pentamidine at 25 μM prevents formation of the catalytically active F band conformation of the precursor RNA and alters the ribonuclease T1 cleavage pattern of Ca.LSU RNA. The effects on cleavage suggest that pentamidine mainly binds to specific sites in or near asymmetric loops of helices P2 and P2.1 on the ribozyme, as well as to the tetraloop of P9.2 and the loosely paired helix P9, resulting in an altered structure of helix P7, which contains the active site. Positively charged molecules antagonize pentamidine inhibition of catalysis and relieve the drug effect on ribozyme folding, suggesting that pentamidine binds to a magnesium binding site(s) of the ribozyme to exert its inhibitory effect.
AB - The antimicrobial agent pentamidine inhibits the self-splicing of the group I intron Ca.LSU from the transcripts of the 26S rRNA gene of Candida albicans, but the mechanism of pentamidine inhibition is not clear. We show that preincubation of the ribozyme with pentamidine enhances the inhibitory effect of the drug and alters the folding of the ribozyme in a pattern varying with drug concentration. Pentamidine at 25 μM prevents formation of the catalytically active F band conformation of the precursor RNA and alters the ribonuclease T1 cleavage pattern of Ca.LSU RNA. The effects on cleavage suggest that pentamidine mainly binds to specific sites in or near asymmetric loops of helices P2 and P2.1 on the ribozyme, as well as to the tetraloop of P9.2 and the loosely paired helix P9, resulting in an altered structure of helix P7, which contains the active site. Positively charged molecules antagonize pentamidine inhibition of catalysis and relieve the drug effect on ribozyme folding, suggesting that pentamidine binds to a magnesium binding site(s) of the ribozyme to exert its inhibitory effect.
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UR - http://www.scopus.com/inward/citedby.url?scp=0036639785&partnerID=8YFLogxK
M3 - Article
C2 - 12087182
AN - SCOPUS:0036639785
VL - 30
SP - 2961
EP - 2971
JO - Nucleic Acids Research
JF - Nucleic Acids Research
SN - 0305-1048
IS - 13
ER -