Poster abstracts

Poster number 40 submitted by Santosh Mahto

Investigation of the structural roles of nucleic acid modification in the bacterial decoding region of 16S rRNA

Santosh K. Mahto (Department of Chemistry, Wayne State University, Detroit , MI 48202), Christine S. Chow (Department of Chemistry, Wayne State University, Detroit , MI 48202)

Abstract:
The translation of genetic information into proteins is a complex process performed by the macromolecule called the ribosome and is an essential process in all cells. The decoding region (helix 44) of 16S ribosomal RNA (rRNA) of the small subunit is a very important functional region; it is involved in binding to mRNA, tRNAs, and the large subunit rRNA. The decoding region is involved in translational accuracy, and is also responsible for translocation. In addition, some of the known antibiotics bind to this region. There are three modified nucleosides in the decoding site of E. coli 16S rRNA, namely 5-methylcytidine (m5C), 3-methyluridine (m3U), and N4, 2\'-O-dimethylcytidine (m4Cm). The functional significance of those modified nucleosides is still not completely understood. Out of the three modified nucleosides, m3U and m5C are commercially available. In contrast, m4Cm, one of the modified nucleosides in which both the base and sugar are methylated is not commercially available. In order to carry out detailed studies on the roles of m4Cm and additional analogues, N4-methylcytidine (m4C) and 2\'-O-methylcytidine (Cm), they were chemically synthesized. The phosphoramidite of m4Cm and its analogs m4C and Cm were prepared and a series of decoding region RNA models were constructed. UV melting was then carried out to determine the stabilizing effects of the methylated nucleosides within the context of the decoding region of 16S rRNA.

Keywords: Modified nucleosides, Decoding region, Ribosomal RNA