title: Putative regulatory sequences for the transcription of mini-exons in Trypanosoma brucei as revealed by S1 sensitivity.
abstract: The 35-nucleotide (nt) mini-exon found at the 5' end of most Trypanosoma brucei mRNAs is encoded as part of a tandem 1.35-kb repeat in genomic DNA. We cloned this DNA and identified an S1-sensitive site in supercoiled plasmids containing mini-exon repeats. This site is situated on a poly(dA-dT) stretch that is variable in length in different copies of repeat. Poly(dA-dT) is capable of forming abnormal DNA helix configurations, some of which are induced by supercoiling. The S1 site may have a role in regulation of mini-exon transcription.
mesh_terms: D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular; D004720:Endonucleases; D005809:Genes, Regulator; D010957:Plasmids; D012333:RNA, Messenger / Q000235:genetics*; D012091:Repetitive Sequences, Nucleic Acid; D015719:Single-Strand Specific DNA and RNA Endonucleases; D014158:Transcription, Genetic; D014346:Trypanosoma brucei brucei / Q000235:genetics*
chemical_list: D012333:RNA, Messenger; D004720:Endonucleases; D015719:Single-Strand Specific DNA and RNA Endonucleases