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Clinical Microbiology: Open Access | ISSN: 2327-5073 | Volume: 7
Microbiology: Education, R&D and Market
7
th
Annual Summit on
September 28-29, 2018 | San Antonio, USA
Investigating the role of arginine phosphorylation in the regulation of Clp protease-mediated
degradation of cellular proteins in
Mycobacterium tuberculosis
Emmanuel Ogbonna
University of Delaware, USA
M
ycobacterium tuberculosis
remains a leading cause of mortality worldwide. Increasing antibiotic resistance associated with
the bacterium makes it critical to study potential targets for development of novel therapeutics. The Clp protease system
which comprises of a peptidase barrel (ClpP) and an unfoldase (ClpC1 or ClpX) has been studied extensively in a host of other
bacteria and is essential for protein homeostasis and viability in mycobacteria. This work proposes to describe the relationship
between arginine phosphorylation tagging (as carried out by a specific arginine kinase McsB which is well characterized in
Bacillus subtilis
) and the biochemical activity of the Clp protease system in
Mycobacterium tuberculosis
. To study the arginine
phosphorylation mechanics further,
in vitro
reconstruction of the McsB-ClpC1P1P2 systemwas done to test the direct correlation
between arginine phosphorylation tag and substrate recognition by ClpC1 and its eventual degradation by the ClpP1P2 peptidase.
Epitope-tagged active-site mutants of ClpP1 and ClpP2 would be utilized in an
in vivo
substrate-trapping analysis to reveal
arginine phosphorylated ClpC1P1P2 substrates within the degradome to be generated upon appropriate affinity-based pull-down
and quantitative mass spectrometry. More specifically, an arginine phosphatase trap (YwlE C7A mutant) has been constructed
and would be used for identification of arginine-phosphorylated substrate proteins and interaction partners in lysate from
Mycobacterium tuberculosis
or its non-pathogenic close relative
M. smegmatis
. In totality, the proposal hypothesizes that arginine
phosphorylation plays a key role in marking protein substrates for Clp-mediated proteolysis in
Mycobacterium tuberculosis.
Biography
Emmanuel Ogbonna is a PhD student at the University of Delaware. He works in the Schmitz Lab in the Department of Biological Sciences, which is a protein
biochemistry and structural biology laboratory that studies the caseinolytic proteases (Clp proteases) in Mycobacterium tuberculosis(Mtb), with the aim of
understanding how the component proteins work, and how they interact with specific substrates. He had previously worked on identifying substrates for the
ClpXP1P2 system in Mtb, but now studies how some of these substrates might be specifically tagged on arginine residues prior to degradation by the Clp
proteasome-like machinery.
eogbonna@udel.eduEmmanuel Ogbonna, Clin Microbiol 2018, Volume: 7
DOI: 10.4172/2327-5073-C3-040