Page 4 - W. RNA biology

[W. RNA biology-2]

NMR structural investigation of pre-miRNA-155 that is

involved in human cancer development

So-young Kim¹˙², Ji Yeon Shin¹, Kyeong-Mi Bang¹, Sungnam Park², Nak-Kyoon Kim¹

¹Advanced Analysis Center, Korea Institute of Science and Technology, Seoul 02792, Republic of Korea,

²Department of Chemistry, Korea University, Seoul 02841, Republic of Korea

MicroRNAs (miRNAs) are short, non-coding single stranded RNAs (ssRNAs) found in eukaryotic cells and some
viruses. Pre-miRNAs are processed into mature miRNA duplexes by an enzyme called Dicer. MiRNA-155 is one of

the miRNAs that suppresses apoptosis in human cancer, causing breast, pancreatic and lung cancer. Previously, we

showed that a synthetic peptide bound to the major groove of pre-miRNA-155 inhibit the Dicer mediated
maturation of the pre-miRNA-155. Therefore, it is important to understand the structural characteristics of pre-
miRNA-155, which are important for recognition of the interacting peptide. Accordingly, NMR spectroscopy was

used to obtain sophisticated tertiary structures of pre-miRNA-155 in solution. At present, in addition to the
previously assigned 1H and 13C resonances, all of the rest 1H and 13C resonances are being assigned. To avoid the

spectral cloudiness observed in large RNA, base-specific 13C- and 15N- labeled RNAs were synthesized and a series
of filtered/edited NOE experiments were examined. With NOE based distance information, an exact structure of the

pre-miRNA-155 will be calculated, and the specific characteristics of miRNA-155 will be identified.