Poster abstracts

Poster number 49 submitted by Abigael Muchenditsi

Effects of metal ions and loop stability tRNA affinity of the T box antiterminator model RNA

Abigael Muchenditsi (Chemistry/Biochemistry, Ohio university), Dr. Jennifer V. Hines (Chemistry/Biochemistry, Ohio university)

Abstract:
The T box family of genes are primarily found in Gram-positive bacteria and are characterized by highly conserved primary and secondary structural elements in the 5’ untranslated region. The expression of the genes (typically related to amino acid biosynthesis) is up regulated by the cognate tRNA interaction with the conserved 5’ untranslated region of the nascent mRNA in at least two positions. One of the interactions involves base pairing of the acceptor end of the tRNA with four base pairs of the bulge in a conserved secondary structural element known as the antiterminator. The antiterminator consists of two helices, A1 and A2 separated by a seven-nucleotide bulge and a closing loop in the A2 helix. The tRNA affinity of antiterminator model RNA with different loops was investigated. The effects of divalent metal ions and loop stability on structure and affinity of the antiterminator model RNA were investigated using computational, spectroscopic and molecular biology methods. The results indicate that divalent metal ions are required for maximal tRNA affinity and that this effect is modulated by the stability of the loop indicating that the overall stability (and possibly flexibility) of the antiterminator plays a role in tRNA binding.

Keywords: T box genes, RNA stability, structure-function, binding