Previous Article | Next Article ![]()
Molecular and Cellular Biology, March 2005, p. 2107-2116, Vol. 25, No. 6
0270-7306/05/$08.00+0 doi:10.1128/MCB.25.6.2107-2116.2005
Copyright © 2005, American Society for Microbiology. All Rights Reserved.
íková1Department of Biochemistry and Molecular Biology, Uniformed Services University of the Health Sciences, Bethesda, Maryland1
Received 10 November 2004/ Returned for modification 6 December 2004/ Accepted 14 December 2004
Both the Prp18 protein and the U5 snRNA function in the second step of pre-mRNA splicing. We identified suppressors of mutant prp18 alleles in the gene for the U5 snRNA (SNR7). The suppressors' U5 snRNAs have either a U4-to-A or an A8-to-C mutation in the evolutionarily invariant loop 1 of U5. Suppression is specific for prp18 alleles that encode proteins with mutations in a highly conserved region of Prp18 which forms an unstructured loop in crystals of Prp18. The snr7 suppressors partly restored the pre-mRNA splicing activity that was lost in the prp18 mutants. The close functional relationship of Prp18 and U5 is emphasized by the finding that two snr7 alleles, U5A and U6A, are dominant synthetic lethal with prp18 alleles. Our results support the idea that Prp18 and the U5 snRNA act in concert during the second step of pre-mRNA splicing and suggest a model in which the conserved loop of Prp18 acts to stabilize the interaction of loop 1 of the U5 snRNA with the splicing intermediates.
This article has been cited by other articles:
Copyright © 2009 by the American Society for Microbiology. For an alternate route to Journals.ASM.org, visit: http://intl-journals.asm.org | More Info»