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Biochemical Study of a New Family of Isomerocyclases in the Biogenesis of Hapalindole Type Alkaloids and Chemical Genetic Approach to Studying Bacterial Chromosome Segregation

Yang, Xiaole (2024) Biochemical Study of a New Family of Isomerocyclases in the Biogenesis of Hapalindole Type Alkaloids and Chemical Genetic Approach to Studying Bacterial Chromosome Segregation. Doctoral Dissertation, University of Pittsburgh. (Unpublished)

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Abstract

Antibiotic resistance presents a growing health challenge that will require a repertoire of new antibiotics that inhibit diverse targets. This includes the characterization of the biosynthesis of hapalindole type alkaloids (HTAs), which are produced by Stigonematalean cyanobacteria. I have also characterized the mechanism of action of a previously known antibiotic that disrupts phase separation of a bacterial biomolecular condensate involved in chromosome segregation. Then, I develop methods to study catalytically dead histidine kinases which are a part of a larger family of histidine kinases that regulate growth, virulence, and biofilm formation. Collectively, my work examines natural products and new antibiotic targets that could ultimately lead the way to next generation of antibiotics.
In chapter 1, a combination of biochemical and biophysics approaches was extensively utilized to elucidate the U-type isomerocyclases heteromeric nature in the biogenesis of hapalindoles with the particular focus on hapalindole U and the confirmation of the calcium co-factor dependency for the U-isomerocyclases enzymatic activities.
Recently, it has been recognized that bacterial cells leverage phase separation to form specialized compartments that regulate essential pathways. Past mechanistic studies suggest disruption of these assembly of these essential compartments could function as new antibiotic targets. In chapter 2, I will explore the discovery of a small molecule that specifically disrupts the phase separation properties of ParB, a CTPase involved in chromosome segregation in diverse bacterial species. Our studies pinpoint towards generalization of identifying lynchpin interactions that control the degree of multivalency as promising drug target strategies for biomolecular condensates associated with pathogens, cancer, and neurodegenerative diseases.
In chapter 3, I will discuss models for how bacterial pseudokinases can utilize protein-protein interactions and allostery to serve as crucial signaling pathway regulators. Then we describe a protein engineering strategy to interrogate these models, emphasizing how signals flow within bacterial pseudokinases.
In summary, the biochemical and biophysical characterizations of bioactive and structurally diverse HTAs biosynthesis will facilitate the structurally complicated small molecule in vitro biosynthesis and the ParB-parS-CTP biomolecular condensate will serve as an effective screening platform for antibiotics discovery.

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Details

Item Type: University of Pittsburgh ETD
Status: Unpublished
Creators/Authors:
CreatorsEmailPitt UsernameORCID
Yang, Xiaolexiy48@pitt.eduXIY48
ETD Committee:
TitleMemberEmail AddressPitt UsernameORCID
Committee ChairChilders, W.Sethwschild@pitt.edu
Committee MemberHorne, Sethhorne@pitt.edu
Committee MemberKabirul, IslamKAI27@pitt.edu
Committee MemberThibodeau, Patrick H.pthibodeau@cff.org
Date: 10 January 2024
Date Type: Publication
Defense Date: 26 May 2023
Approval Date: 10 January 2024
Submission Date: 3 December 2023
Access Restriction: 2 year -- Restrict access to University of Pittsburgh for a period of 2 years.
Number of Pages: 165
Institution: University of Pittsburgh
Schools and Programs: Dietrich School of Arts and Sciences > Chemistry
Degree: PhD - Doctor of Philosophy
Thesis Type: Doctoral Dissertation
Refereed: Yes
Uncontrolled Keywords: Antibiotics, Hapalindole, Biosynthesis, Biomolecular Condensate, Chromosome segaregation, ParB, CTPase, Pseudokinases, cloning.
Date Deposited: 10 Jan 2024 14:20
Last Modified: 10 Jan 2024 14:20
URI: http://d-scholarship.pitt.edu/id/eprint/45631

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  • Biochemical Study of a New Family of Isomerocyclases in the Biogenesis of Hapalindole Type Alkaloids and Chemical Genetic Approach to Studying Bacterial Chromosome Segregation. (deposited 10 Jan 2024 14:20) [Currently Displayed]

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