Date Available
5-24-2012
Year of Publication
2012
Document Type
Master's Thesis
Degree Name
Master of Science (MS)
College
Arts and Sciences
Department/School/Program
Chemistry
Advisor
Dr. Yinan Wei
Abstract
SurA is a molecular chaperone in the periplasm of E.coli and has been implicated in the maturation of outer membrane proteins (OMPs). SurA consists of four domains, but only two of them, namely the N and C-terminal domains, are necessary for chaperone function. Very little is known about which residues drive the interaction between the N and C-termini that facilitates normal activity. We mutated several conserved residues on the C-terminus and generated additive truncations to observe the effects of each on the fitness of the cell. We found one mutation E(408):A was sufficient to reduce SurA activity by 3-fold, but structural characterization of the mutated protein revealed little variation from wild-‐type SurA. Most notable, we found that when at least 10 residues are removed from the C-‐terminus, the protein is completely non-‐functional. We introduced a random peptide library to substitute these 10 residues and found that ~1.5% of all possible sequences in the library can restore SurA function to at least 50% activity. Moreover, we observed no pattern in the sequences of 26 different variants that were chosen and characterized. Here we show for the first time that SurA can tolerate many mutations at the C-terminus and still be active.
Recommended Citation
Ferrell, Brent, "INVESTIGATION OF THE CRITICAL RESIDUES AT THE C-TERMINUS OF THE E.COLI PERIPLASMIC CHAPERONE, SURA" (2012). Theses and Dissertations--Chemistry. 8.
https://uknowledge.uky.edu/chemistry_etds/8
