Date of Award
January 2016
Degree Type
Thesis
Degree Name
Master of Science (MS)
Department
PULSe
First Advisor
Chittaranjan Das
Committee Member 1
Jean-Christophe Rochet
Committee Member 2
Mark Hall
Committee Member 3
Andrew Mesecar
Abstract
ElaD is a cysteine protease found in Escherichia coli (E. coli) and has been shown to function as a deubiquitinating enzyme (DUB). However, ubiquitin and the ubiquitination system are exclusive to eukaryotic cells. This indicates that ElaD may be used when the bacteria come in contact with a eukaryotic cell. This explains its presence in the intestinally infective strains of E. coli. For the invasive strains of E. coli, membrane fusion and phagosome formation is used for entry of the infective cell into the host cell. In order to counteract this, ubiquitination, the eukaryotic cell’s first defense mechanism, is used to signal for degradation of the phagosome. The phagosome is signaled for degradation by the host via adornment of the phagosome with Lys63-linked ubiquitin chains. We hypothesize that ElaD is used to neutralize ubiquitination of the phagosome and prevent destruction of the bacteria. With this hypothesis in mind we seek to examine the substrate preference of the DUB using diubiquitin substrates of defined linkage types. In addition we wish to understand the role of the active-site loop in determining selectivity of the DUB for ubiquitin over a ubiquitin-like modifier Nedd8.
Recommended Citation
Wade, Cameron, "Biochemical Analysis of a Prokaryotic Deubiquitinase from Escherichia Coli" (2016). Open Access Theses. 1233.
https://docs.lib.purdue.edu/open_access_theses/1233