Open AccessLinker scanner mutagenesis of theXenopus laevisribosomal gene promoter
Author(s) -
Ronald H. Reeder,
David G. Pennock,
Brian McStay,
Judith G. Roan,
Ernie Tolentino,
Philippe Walker
Publication year - 1987
Publication title -
nucleic acids research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 9.008
H-Index - 537
eISSN - 1362-4954
pISSN - 0305-1048
DOI - 10.1093/nar/15.18.7429
Subject(s) - biology , xenopus , mutagenesis , gene , ribosomal rna , genetics , ribosomal dna , microbiology and biotechnology , mutation , phylogenetics
We have assayed a series of linker scanner mutants which cover the Xenopus laevis ribosomal gene promoter at approximately ten base pair intervals. All of these mutations adversely affect promoter activity with the exception of one mutation which stimulates activity. Thus, none are neutral. We show that most of the mutations can be partially rescued by ligating a block of enhancer elements upstream of the promoter. In addition, we have made extracts from liver nuclei which produce DNaseI protection footprints over the promoter. Analysis of both strands reveals a prominent footprinting domain from about -5 to -30. However, lesser changes in the digestion pattern are detected over most of the promoter. Previously published analyses have suggested that this promoter might be composed of three functional domains. The experiments presented here suggest that either 1) the three putative domains are so closely arranged that the boundaries are difficult to discern, or 2) the situation is more complex.