Characterization of the partitioning protein ParB in Caulobacter crescentus

Joo, Daniel Lee

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https://hdl.handle.net/2142/120588 Copy

Description

Title

Characterization of the partitioning protein ParB in Caulobacter crescentus

Author(s)

Joo, Daniel Lee

Issue Date

2023-05-04

Director of Research (if dissertation) or Advisor (if thesis)

Mera, Paola E

Department of Study

Microbiology

Discipline

Microbiology

Degree Granting Institution

University of Illinois at Urbana-Champaign

Degree Name

M.S.

Degree Level

Thesis

Keyword(s)

• chromosome segregation
• ParB
• Caulobacter
• cell cycle

Abstract

Maintaining chromosome integrity during the cell cycle is essential for bacterial survival. The ParABS partitioning system is involved in coordinating chromosome segregation during bacterial cell cycle. ParB plays an important role in coordinating many cell cycle steps such as chromosome segregation, polar anchoring, loading of the structural maintenance complex protein, and localization of the Z-ring in the bacterial system Caulobacter crescentus (referred here as Caulobacter). However, our understanding of the various potential functions of ParB’s N-terminal domain remains limited. My data indicate that the Caulobacter utilizes the first start codon between the two possible start codons to express the native form of ParB. This discovery is crucial in the field since the two start codons have been used in the literature indiscriminately. I have shown that cells expressing from each start codon display different phenotypes. I have also shown that the expression of the N-terminus truncated parB is lethal even when there is minimal accumulation of this variant protein in the cell. I isolated a suppressor mutant that rescued the lethal effect from the expression of N-terminus truncated parB. Further characterization of this suppressor is needed to determine the mechanism involved in the lethality from expression of N-terminus truncated parB. Further understanding of this key cell cycle regulator and its various functions will advance our knowledge of bacterial cell cycle regulation. This information has the potential to contribute insights to our ability of controlling bacterial growth by manipulating its cell cycle.

Graduation Semester

2023-05

Type of Resource

Thesis

Handle URL

https://hdl.handle.net/2142/120588

Copyright and License Information

Copyright 2023 Daniel Joo

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