Nucleic Acids Research, 2002, Vol. 30, No. 13 2961-2971
© 2002 Oxford University Press
Pentamidine inhibits catalytic activity of group I intron Ca.LSU by altering RNA folding
1 Department of Biotechnology, College of Life Science, Wuhan University, Wuhan, Hubei 430072, China, 2 Department of Molecular Genetics and Microbiology and 3 Department of Pharmacology, University of Medicine and Dentistry of New Jersey–Robert Wood Johnson Medical School, Piscataway, NJ 08854, USA and 4 The Cancer Institute of New Jersey, New Brunswick, NJ 08901, USA
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.
* To whom correspondence should be addressed at: Department of Molecular Genetics and Microbiology, University of Medicine and Dentistry of New Jersey–Robert Wood Johnson Medical School, 675 Hoes Lane, Piscataway, NJ 08854-5635, USA. Tel: +1 732 235 4795; Fax: +1 732 235 5223; Email: leibowit{at}umdnj.edu
CiteULike 
Connotea 
Del.icio.us What's this?
This article has been cited by other articles:
|
|
 |
|
  M. B. Warf, M. Nakamori, C. M. Matthys, C. A. Thornton, and J. A. Berglund From the Cover: Pentamidine reverses the splicing defects associated with myotonic dystrophy PNAS, November 3, 2009; 106(44): 18551 - 18556. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 L. Zhang, P. Bao, M. J. Leibowitz, and Y. Zhang Slow formation of a pseudoknot structure is rate limiting in the productive co-transcriptional folding of the self-splicing Candida intron RNA, November 1, 2009; 15(11): 1986 - 1992. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 T. Sun and Y. Zhang Pentamidine binds to tRNA through non-specific hydrophobic interactions and inhibits aminoacylation and translation Nucleic Acids Res., March 1, 2008; 36(5): 1654 - 1664. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. T. Cushion, P. D. Walzer, A. Ashbaugh, S. Rebholz, R. Brubaker, J. J. Vanden Eynde, A. Mayence, and T. L. Huang In Vitro Selection and In Vivo Efficacy of Piperazine- and Alkanediamide-Linked Bisbenzamidines against Pneumocystis Pneumonia in Mice. Antimicrob. Agents Chemother., July 1, 2006; 50(7): 2337 - 2343. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. T. Cushion, P. D. Walzer, M. S. Collins, S. Rebholz, J. J. Vanden Eynde, A. Mayence, and T. L. Huang Highly Active Anti-Pneumocystis carinii Compounds in a Library of Novel Piperazine-Linked Bisbenzamidines and Related Compounds Antimicrob. Agents Chemother., November 1, 2004; 48(11): 4209 - 4216. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. Xiao, M. J. Leibowitz, and Y. Zhang Concerted folding of a Candida ribozyme into the catalytically active structure posterior to a rapid RNA compaction Nucleic Acids Res., July 15, 2003; 31(14): 3901 - 3908. [Abstract] [Full Text] [PDF]
|
|