Degree Type
Dissertation
Date of Award
2005
Degree Name
Doctor of Philosophy
Department
Biochemistry, Biophysics and Molecular Biology
First Advisor
Gloria M. Culver
Abstract
The purpose of this course of study is to understand the conformational changes that occur in 16S rRNA during ribosomal assembly. The prokaryotic ribosome comprises two asymmetric subunits, the large (50S) and small (30S) subunits. The 30S subunit contains 16S rRNA and the small ribosomal proteins (S1--S21). Functional 30S ribosomal subunits can be reconstituted in vitro from purified components. Reconstitution performed at low temperatures results in a stall in 30S subunit assembly. This stall produces a R&barbelow;econstitution I&barbelow;ntermediate (RI) which sediments at 21S and contains 16S rRNA and a subset of small subunit proteins. In order for RI to be converted into functional 30S subunits, a temperature shift is first required. This shift produces a particle, RI*, with the same composition as RI, yet a dramatically different sedimentation coefficient (26S). RI* can then go on to bind the remaining small subunit proteins, ultimately resulting in functional 30S subunit formation. To better understand the nature of these assembly transitions and thus small subunit assembly, changes in reactivity of each nucleotide during the course of assembly was monitored. The changes in reactivity of nucleotides in 16S rRNA between each of the assembly species (16S, RI, RI* and 30S) were analyzed in the context of the 30S subunit structure and previous biochemical studies to better understand the relationship between ribosomal assembly and function.
DOI
https://doi.org/10.31274/rtd-180813-8761
Publisher
Digital Repository @ Iowa State University, http://lib.dr.iastate.edu
Copyright Owner
Kristi L. Holmes
Copyright Date
2005
Language
en
Proquest ID
AAI3184621
File Format
application/pdf
File Size
110 pages
Recommended Citation
Holmes, Kristi L., "Understanding 16S ribosomal RNA conformational changes during 30S subunit assembly " (2005). Retrospective Theses and Dissertations. 1563.
https://lib.dr.iastate.edu/rtd/1563