Downstream elements of mammalian pre-mRNA polyadenylation signals: primary, secondary and higher-order structures.
Primary, secondary and higher-order structures of downstream elements of mammalian pre-mRNA polyadenylation signals [poly(A) signals] are re viewed. We have carried out a detailed analysis on our database of 244 human pre-mRNA poly(A) signals in order to characterize elements in their downstream regions. We suggest that the downstream region of the mammalian pre-mRNA poly(A) signal consists of various simple elements located at different distances from each other. Thus, the downstream region is not described by any precise consensus. Searching our database, we found that approximately 80% of pre-mRNAs with the AAUAAA or AUUAAA core upstream elements contain simple downstream elements, consisting of U-rich and/or 2GU/U tracts, the former occurring approximately 2-fold more often than the latter. Approximately one-third of the pre-mRNAs analyzed here contain sequences that may form G-quadruplexes. A substantial number of these sequences are located immediately downstream of the poly(A) signal. A possible role of G-rich sequences in the polyadenylation process is discussed. A model of the secondary structure of the SV40 late pre-mRNA poly(A) signal downstream region is presented.
Zarudnaya
Margarita I
MI
Molecular Biophysics Department, Institute of Molecular Biology and Genetics, National Academy of Sciences of Ukraine, 150, vul. Zabolotnoho, Kyiv, 03143, Ukraine. dhovorun@imbg.org.ua
Kolomiets
Iryna M
IM
Potyahaylo
Andriy L
AL
Hovorun
Dmytro M
DM
D000818:Animals; D001483:Base Sequence; D006801:Humans; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D011061:Poly A / Q000737:chemistry* / Q000235:genetics; D012322:RNA Precursors / Q000737:chemistry* / Q000235:genetics; D015398:Signal Transduction
D012322:RNA Precursors; D011061:Poly A