| dc.identifier.uri | http://hdl.handle.net/11401/76466 | |
| dc.description.sponsorship | This work is sponsored by the Stony Brook University Graduate School in compliance with the requirements for completion of degree. | en_US |
| dc.format | Monograph | |
| dc.format.medium | Electronic Resource | en_US |
| dc.language.iso | en_US | |
| dc.publisher | The Graduate School, Stony Brook University: Stony Brook, NY. | |
| dc.type | Dissertation | |
| dcterms.abstract | In nature, most bacteria live in surface attached communities called bacterial biofilms. Community living is beneficial to the bacteria, as it offers heightened resistance to environmental stresses due to the production of a protective exopolymeric matrix. When the growth of a bacterial community reaches a certain threshold, some bacteria disperse to find new frontiers to occupy and repopulate. Bacterial biofilms can be beneficial as is the case with those found in our gastrointestinal tracks that help us digest food particles. However, biofilms can pose a major threat to human health when they are composed of pathogenic bacteria that cause chronic infections. In order for bacteria to switch between a free-swimming and biofilm state, they respond to various environmental stimuli, including nitric oxide (NO), a diatomic gas molecule that has been shown to modulate biofilm formation in many bacteria. In some bacteria, NO is sensed by the H-NOX (heme nitric oxide/oxygen binding protein) protein, a homologue of a mammalian nitric oxide sensor, the heme containing soluble guanylate cyclase (sGC). However, many bacteria that respond to NO, including the opportunisticpathogen Pseudomonas aeruginosa, lack an hnoX gene; therefore, suggesting the presence of an alternative NO sensing protein. In this dissertation, I present the discovery of a novel NO sensing protein (NosP). NosPs, like H-NOX proteins, are typically organized within bacterial genomes in operons with signaling proteins that lack known sensing modules. We demonstrate that Pseudomonas aeruginosa NosP is able to ligate to NO via the ferrous iron of a heme cofactor. By disrupting a NosP associated histidine kinase, I illustrate a defect in NO- mediated biofilm dispersal in Pseudomonas aeruginosa. Further, I investigated the pattern of NosP and NosP associated effector protein signaling biochemically within Pseudomonas aeruginosa, Vibrio cholerae, and Legionella pneumophila. Finally, I characterized NosPs from Vibrio harveyi and Shewanella woodyi spectroscopically to identify similarities of their ligand binding properties. Considering all the findings, I propose that NosP is a primary NO sensor that shares no sequence homology with the H-NOX proteins. Thus, for the first time, I highlight a novel NO signaling pathway in bacteria, providing a strong foundation for future research. | |
| dcterms.available | 2017-09-20T16:50:20Z | |
| dcterms.contributor | Boon, Elizabeth M | en_US |
| dcterms.contributor | Seeliger, Jessica C | en_US |
| dcterms.contributor | London, Erwin | en_US |
| dcterms.contributor | Green, David | en_US |
| dcterms.contributor | Johnson, Roger. | en_US |
| dcterms.creator | Hossain, Sajjad | |
| dcterms.dateAccepted | 2017-09-20T16:50:20Z | |
| dcterms.dateSubmitted | 2017-09-20T16:50:20Z | |
| dcterms.description | Department of Molecular and Cellular Biology | en_US |
| dcterms.extent | 135 pg. | en_US |
| dcterms.format | Application/PDF | en_US |
| dcterms.format | Monograph | |
| dcterms.identifier | http://hdl.handle.net/11401/76466 | |
| dcterms.issued | 2016-12-01 | |
| dcterms.language | en_US | |
| dcterms.provenance | Made available in DSpace on 2017-09-20T16:50:20Z (GMT). No. of bitstreams: 1
Hossain_grad.sunysb_0771E_13135.pdf: 12784405 bytes, checksum: 409c3c07c398545f7f4dbb164ec3ae16 (MD5)
Previous issue date: 1 | en |
| dcterms.publisher | The Graduate School, Stony Brook University: Stony Brook, NY. | |
| dcterms.subject | Molecular biology -- Biochemistry -- Microbiology | |
| dcterms.title | Discovery of a Novel Nitric Oxide Sensing Protein, NosP | |
| dcterms.type | Dissertation | |
