title: Analysis of the 5'-AAUAAA motif and its flanking sequence in human RNA: relevance to cDNA library sorting.
abstract: The motif, N-8..N-1AAUAAAN1..N8 (where N is A, C, G or U), and its flanking sequence in human mRNA were examined by database analysis. Approximately 20% of 5'-AAUAAA in 3'-noncoding regions appear not to direct mRNA cleavage-polyadenylation. In coding regions, Asn-Lys, Ile-Lys and Ile-Asn are proven not to be unfavourable, and AAUAAA is not an unfavourable choice of coding sequence, occurring in 16% of mRNAs. Neither immediate flanking sequence nor associated motifs bear sufficient information content to account for the cleavage specificity observed. The unusual distribution and properties of the motif, AATAAA, in cDNA invite novel strategies for sorting cDNA libraries.
authors.affiliation: South Laboratory, Southampton General Hospital, U.K.
authors.forename: I N
authors.initials: IN
authors.lastname: Day
mesh_terms: D001483:Base Sequence; D016208:Databases, Factual; D015723:Gene Library; D015894:Genome, Human; D006801:Humans; D008433:Mathematics; D008969:Molecular Sequence Data; D011061:Poly A / Q000235:genetics*; D011506:Proteins / Q000235:genetics; D012333:RNA, Messenger / Q000235:genetics*
chemical_list: D011506:Proteins; D012333:RNA, Messenger; D011061:Poly A