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12 results on '"Keen, Edward F"'

9. Transcription Activation by Escherichia coli Rob at Class II Promoters: Protein–Protein Interactions between Rob's N-Terminal Domain and the σ70 Subunit of RNA Polymerase

Author

Taliaferro, Lanyn P., Keen, Edward F., Sanchez-Alberola, Neus, and Wolf, Richard E.

Subjects
*GENETIC transcription, *ESCHERICHIA coli, *PROTEIN-protein interactions, *PROMOTERS (Genetics), *RNA polymerases, *TRANSCRIPTION factors
Abstract

Abstract: Bacterial transcription activators regulate transcription by making essential protein–protein interactions with RNA polymerase, for example, with region 4 of the σ70 subunit (σ70 R4). Rob, SoxS, and MarA comprise a closely related subset of members of the AraC/XylS family of transcription factors that activate transcription of both class I and class II promoters. Recently, we showed that interactions between SoxS and σ70 R4 occlude the binding of σ70 R4 to the −35 promoter element of class II promoters. Although Rob shares many similarities with SoxS, it contains a C-terminal domain (CTD) that the other paralogs do not. Thus, a goal of this study was to determine whether Rob makes protein–protein interactions with σ70 R4 at class II promoters and, if so, whether the interactions occlude the binding of σ70 R4 to the −35 hexamer despite the presence of the CTD. We found that although Rob makes fewer interactions with σ70 R4 than SoxS, the two proteins make the same, unusual, position-dependent interactions. Importantly, we found that Rob occludes σ70 R4 from binding the −35 hexamer, just as does SoxS. Thus, the CTD does not substantially alter the way Rob interacts with σ70 R4 at class II promoters. Moreover, in contrast to inferences drawn from the co-crystal structure of Rob bound to robbox DNA, which showed that only one of Rob''s dual helix–turn–helix (HTH) DNA binding motifs binds a recognition element of the promoter''s robbox, we determined that the two HTH motifs each bind a recognition element in vivo. [Copyright &y& Elsevier]

Published
2012
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10. Evolution of a leader: an assessment of Major General George Izard's leadership in the War of 1812.

Author

Keen, Edward F., III, Keen, Edward F., III, Keen, Edward F., III, and Keen, Edward F., III

Abstract

Poor military and political leadership during the first two years of the War of 1812 resulted in two failed attempts by American armies to invade Canada. These disasters prompted the purging of incompetent and aging Revolutionary War veterans from the upper echelons of the army and their replacement with younger and more capable officers. In 1814, George Izard at 38 years old became one of the youngest major generals in U.S. Army history. The only general officer in the war to have received formal military training in Europe, expectations ran high that Major General Izard would turn the tide of the war in the American's favor. Despite his exemplary military performance in 1812 and 1813, Izard's generalship during the 1814 Niagara Campaign received criticism from contemporaries and historians for failing to act decisively. At the start of the campaign he found himself in command with uncoordinated and poorly communicated strategic objectives, a split command in the 9th Military District, and a Secretary of War attempting to control activities from Washington D.C. For these reasons, a deep analysis of Izard's performance is needed to determine whether his leadership furthered or hindered the strategic and operational goals of the theater of operations.

11. Prevalence of methicillin-resistant staphylococcus aureus in a combat support hospital in Iraq.

Author

Co, Edgie-Mark, Keen, Edward F, and Aldous, Wade K

Abstract

Methicillin-resistant Staphylococcus aureus (MRSA) in health-care settings results in life-threatening infections. We examined the incidence of MRSA at the combat support hospital located at the Ibn Sina Hospital in Baghdad, Iraq. We compiled isolate data from 2005 to 2009 characterizing antibiotic susceptibilities, annual trends, patient populations, infection sites, and hospital locations. Approximately 46.1% of S. aureus were MRSA, with increase in numbers of yearly isolates. MRSA was isolated in higher numbers from U.S. military personnel. Non-U.S. patient isolates displayed higher antibiotic susceptibility compared to U.S. military personnel isolates. Outpatient clinic, forward operating bases, and intermediate care ward 1 isolated the most MRSA. Common isolation sites were wound and skin cultures. Community-acquired MRSA was likely present in 291 out of 303 isolates based on antibiotic susceptibility. Our data suggests that most MRSA were community-acquired with limited nosocomial spread. We recommend increases in combat support hospital molecular lab capability to rapidly identify both MRSA categories.

Published
2011
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