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You searched for subject:(Chloracidobacterium thermophilum). Showing records 1 – 2 of 2 total matches.

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Penn State University

1. Romberger, Steven Paul. STRUCTURE-FUNCTION STUDIES OF HOMODIMERIC TYPE I REACTION CENTERS FROM AN ANAEROBIC AND AN AEROBIC BACTERIUM.

Degree: 2011, Penn State University

The prediction, based on sequence data, that the aerobe Candidatus Chloracidobacterium thermophilum possesses a homodimeric Type I RC, which had previously only been found in anaerobic bacteria, poised the question of how this group of RCs has been modified in response to their respective oxic or anoxic environment. The work described in this dissertation addresses that question by studing the RCs from the strict anaerobe Heliobacterium modesticaldum and the aerobe “Ca. C. thermophilum”. In the heliobacteria, the discovery of a second weakly bound FA/FB-harboring protein, named PshBII, broke the paradigm that defined Type I RCs in terms of a single FA/FB-harboring subunit. This finding suggested that the electron donor to PshBI and PshBII, the interpolypeptide [4Fe-4S] cluster called Fx, was promiscuous and capable of reducing multiple acceptor proteins. As a consequence of this hypothesis, PshBI and PshBII became semi-mobile members of the heliobacterial RC (HbRC): first accepting electrons from the HbRC, then dissociating from the complex and acting directly as ferredoxins in downstream metabolic processes. The promiscuity of Fx was confirmed by the discovery that this iron-sulfur cluster directly reduces cyanobacterial flavodoxin (Fld), a soluble redox protein. Unexpectedly, PshBI and PshBII inhibited Fld reduction, a phenomenon that can be explained based on the competition for the electron on reduced Fx and which supports the role of PsBI and PshBII as semi-mobile members of the HbRC. In “Ca. C. thermophilum”, a homodimeric Type I RC was isolated that retained much greater activity under oxic conditions than the HbRC. The “Ca. C. thermophilum” RC consisted of a core PscA homodimer and several subunits of a novel carotenoid binding protein (CBP), which gives the RC an unusually high carotenoid to chlorophyll ratio. Spectroscopic and biochemical studies indicate that the RC binds bacteriochlorophyll a, zinc-containing bacteriochlorophyll a and chlorophyll a. A large, light-induced bleaching at 840 nm is ascribable to the primary donor. Isolated RCs that were depleted in CBP content showed reduced activity under oxic conditions. Reconstituion of CBP-deplete RCs with excess CBP did not restore activity, indicating that the CBP is necessary, but not sufficient, to explain the oxygen tolerance of the “Ca. C. thermophilum” RC. Advisors/Committee Members: John H Golbeck, Dissertation Advisor/Co-Advisor, John H Golbeck, Committee Chair/Co-Chair, Donald Ashley Bryant, Committee Chair/Co-Chair, Sarah Ellen Ades, Committee Member, Katsuhiko Murakami, Committee Member, Wayne Roger Curtis, Committee Member.

Subjects/Keywords: photosynthesis; phototrophy; heliobacteria; Chloracidobacterium thermophilum; type I reaction center; iron-sulfur cluster

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Romberger, S. P. (2011). STRUCTURE-FUNCTION STUDIES OF HOMODIMERIC TYPE I REACTION CENTERS FROM AN ANAEROBIC AND AN AEROBIC BACTERIUM. (Thesis). Penn State University. Retrieved from https://submit-etda.libraries.psu.edu/catalog/12531

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16th Edition):

Romberger, Steven Paul. “STRUCTURE-FUNCTION STUDIES OF HOMODIMERIC TYPE I REACTION CENTERS FROM AN ANAEROBIC AND AN AEROBIC BACTERIUM.” 2011. Thesis, Penn State University. Accessed October 21, 2020. https://submit-etda.libraries.psu.edu/catalog/12531.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7th Edition):

Romberger, Steven Paul. “STRUCTURE-FUNCTION STUDIES OF HOMODIMERIC TYPE I REACTION CENTERS FROM AN ANAEROBIC AND AN AEROBIC BACTERIUM.” 2011. Web. 21 Oct 2020.

Vancouver:

Romberger SP. STRUCTURE-FUNCTION STUDIES OF HOMODIMERIC TYPE I REACTION CENTERS FROM AN ANAEROBIC AND AN AEROBIC BACTERIUM. [Internet] [Thesis]. Penn State University; 2011. [cited 2020 Oct 21]. Available from: https://submit-etda.libraries.psu.edu/catalog/12531.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Romberger SP. STRUCTURE-FUNCTION STUDIES OF HOMODIMERIC TYPE I REACTION CENTERS FROM AN ANAEROBIC AND AN AEROBIC BACTERIUM. [Thesis]. Penn State University; 2011. Available from: https://submit-etda.libraries.psu.edu/catalog/12531

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

2. Sukmana, Andreas Binar Aji. Understanding PilB, The Type IV Pilus (T4P) Assembly ATPase.

Degree: MS, Biological Sciences, 2018, Virginia Tech

The type IV pilus (T4P) is a dynamic long thin fiber found on the surface of many bacterial groups. T4P is a versatile nanomachine; it plays many important roles such as for surface attachment, virulence factor, and surface motility apparatus. This research focuses on understanding the kinetics of PilB, the T4P assembly ATPase. PilB crystal structure exhibits an elongated hexamer with 2-fold symmetry indicating a symmetric rotary mechanism model. Except for its structure, the symmetric rotary mechanism of PilB has not been demonstrated experimentally. Its conformation and relatively low activity constrained previous in vitro studies of PilB. This study identified PilB from thermophilic organism Chloracidobacterium thermophilum (Ct) to be a model for in vitro studies. An active CtPilB was successfully expressed and purified as a hexamer. Malachite green phosphate assay was used to examine CtPilB ATPase activity. The examination indicated that CtPilB is a robust ATPase with a complex kinetics profile. The profile has a stepwise incline in ATPase activity as a function of [ATP] that led to a decline in higher [ATP]. The decline was confirmed to be a substrate inhibition by the enzyme-coupled assay. As for the incline, the detailed mechanism is still less clear to explain the multiphasic profile. The overall incline did not conform with classical Michaelis-Menten kinetic but the first part of the incline was shown to conform with Michaelis-Menten kinetics. The complex kinetics profile of PilB is consistent with the symmetric rotary mechanism of catalysis. Advisors/Committee Members: Yang, Zhaomin (committeechair), Schubot, Florian David (committee member), Klemba, Michael Wade (committee member).

Subjects/Keywords: Type IV Pilus; Chloracidobacterium thermophilum; PilB; ATPase; Kinetics

Chloracidobacterium thermophilum is a robust hexameric ATPase with complex kinetics Andreas Sukmana and… …sequence of Chloracidobacterium thermophilum identified a pilB gene whose protein we then… …phototrophic bacterium Chloracidobacterium thermophilum (52-54). Analysis of the genome… …RESULTS Chloracidobacterium thermophilum has a full complement of genes for T4aP ― The… …identified a mutant pilB gene in the genomic DNA of C. thermophilum from an enrichment culture. The… 

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Sukmana, A. B. A. (2018). Understanding PilB, The Type IV Pilus (T4P) Assembly ATPase. (Masters Thesis). Virginia Tech. Retrieved from http://hdl.handle.net/10919/83819

Chicago Manual of Style (16th Edition):

Sukmana, Andreas Binar Aji. “Understanding PilB, The Type IV Pilus (T4P) Assembly ATPase.” 2018. Masters Thesis, Virginia Tech. Accessed October 21, 2020. http://hdl.handle.net/10919/83819.

MLA Handbook (7th Edition):

Sukmana, Andreas Binar Aji. “Understanding PilB, The Type IV Pilus (T4P) Assembly ATPase.” 2018. Web. 21 Oct 2020.

Vancouver:

Sukmana ABA. Understanding PilB, The Type IV Pilus (T4P) Assembly ATPase. [Internet] [Masters thesis]. Virginia Tech; 2018. [cited 2020 Oct 21]. Available from: http://hdl.handle.net/10919/83819.

Council of Science Editors:

Sukmana ABA. Understanding PilB, The Type IV Pilus (T4P) Assembly ATPase. [Masters Thesis]. Virginia Tech; 2018. Available from: http://hdl.handle.net/10919/83819

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