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Full-Text Articles in Medical Molecular Biology

Interplay Between An Atp-Binding Cassette F Protein And The Ribosome From Mycobacterium Tuberculosis, Zhicheng Cui, Xiaojun Li, Joonyoung Shin, Howard Gamper, Ya-Ming Hou, James C Sacchettini, Junjie Zhang Jan 2022

Interplay Between An Atp-Binding Cassette F Protein And The Ribosome From Mycobacterium Tuberculosis, Zhicheng Cui, Xiaojun Li, Joonyoung Shin, Howard Gamper, Ya-Ming Hou, James C Sacchettini, Junjie Zhang

Department of Biochemistry and Molecular Biology Faculty Papers

EttA, energy-dependent translational throttle A, is a ribosomal factor that gates ribosome entry into the translation elongation cycle. A detailed understanding of its mechanism of action is limited due to the lack of high-resolution structures along its ATPase cycle. Here we present the cryo-electron microscopy (cryo-EM) structures of EttA from Mycobacterium tuberculosis (Mtb), referred to as MtbEttA, in complex with the Mtb 70S ribosome initiation complex (70SIC) at the pre-hydrolysis (ADPNP) and transition (ADP-VO4) states, and the crystal structure of MtbEttA alone in the post-hydrolysis (ADP) state. We observe that MtbEttA binds the E-site of the Mtb 70SIC, remodeling the …


Distinct Mechanisms Control Genome Recognition By P53 At Its Target Genes Linked To Different Cell Fates., Marina Farkas, Hideharu Hashimoto, Yingtao Bi, Ramana V Davuluri, Lois Resnick-Silverman, James J. Manfredi, Erik W. Debler, Steven B. Mcmahon Jan 2021

Distinct Mechanisms Control Genome Recognition By P53 At Its Target Genes Linked To Different Cell Fates., Marina Farkas, Hideharu Hashimoto, Yingtao Bi, Ramana V Davuluri, Lois Resnick-Silverman, James J. Manfredi, Erik W. Debler, Steven B. Mcmahon

Department of Biochemistry and Molecular Biology Faculty Papers

The tumor suppressor p53 integrates stress response pathways by selectively engaging one of several potential transcriptomes, thereby triggering cell fate decisions (e.g., cell cycle arrest, apoptosis). Foundational to this process is the binding of tetrameric p53 to 20-bp response elements (REs) in the genome (RRRCWWGYYYN0-13RRRCWWGYYY). In general, REs at cell cycle arrest targets (e.g. p21) are of higher affinity than those at apoptosis targets (e.g., BAX). However, the RE sequence code underlying selectivity remains undeciphered. Here, we identify molecular mechanisms mediating p53 binding to high- and low-affinity REs by showing that key determinants of the code are embedded …


Transplantation Of Thioredoxin-1 Exosomes In A Murine Model Of Hind-Limb Ischemia: A Novel Therapeutic Approach, Shubham Kanake May 2018

Transplantation Of Thioredoxin-1 Exosomes In A Murine Model Of Hind-Limb Ischemia: A Novel Therapeutic Approach, Shubham Kanake

Honors Scholar Theses

Peripheral artery disease is one of the most prevalent cardiovascular diseases in the United States and worldwide. It is estimated that over 8 million people in the United States are affected with peripheral artery disease, and up to 40% of people over 80 years old may have some degree of the disease. Peripheral artery disease can increase one’s chances for having other cardiovascular co-morbidities such as coronary artery disease, among others. Current interventional strategies are endovascular treatments such as transluminal angioplasty and stenting, or in more advanced cases peripheral artery bypass grafting. Medical interventions focus on managing symptoms and treating …


Changing Diagnostic Methods And Increased Detection Of Verotoxigenic Escherichia Coli, Ireland, Thomas Rice, Noreen Quinn, Roy D. Sleator, Brigid Lucey Sep 2016

Changing Diagnostic Methods And Increased Detection Of Verotoxigenic Escherichia Coli, Ireland, Thomas Rice, Noreen Quinn, Roy D. Sleator, Brigid Lucey

Department of Biological Sciences Publications

The recent paradigm shift in infectious disease diagnosis from culture-based to molecular-based approaches is exemplified in the findings of a national study assessing the detection of verotoxigenic Escherichia coli infections in Ireland. The methodologic changes have been accompanied by a dramatic increase in detections of non-O157 verotoxigenic E. coli serotypes.


Conservation Of Structure And Mechanism By Trm5 Enzymes., Thomas Christian, Howard Gamper, Ya-Ming Hou Sep 2013

Conservation Of Structure And Mechanism By Trm5 Enzymes., Thomas Christian, Howard Gamper, Ya-Ming Hou

Department of Biochemistry and Molecular Biology Faculty Papers

Enzymes of the Trm5 family catalyze methyl transfer from S-adenosyl methionine (AdoMet) to the N¹ of G37 to synthesize m¹ G37-tRNA as a critical determinant to prevent ribosome frameshift errors. Trm5 is specific to eukaryotes and archaea, and it is unrelated in evolution from the bacterial counterpart TrmD, which is a leading anti-bacterial target. The successful targeting of TrmD requires detailed information on Trm5 to avoid cross-species inhibition. However, most information on Trm5 is derived from studies of the archaeal enzyme Methanococcus jannaschii (MjTrm5), whereas little information is available for eukaryotic enzymes. Here we use human Trm5 (Homo sapiens; HsTrm5) …


Development Of A Protocol To Measure Gene Expression In The Mouse Tibia, Daniel Hoover Jun 2012

Development Of A Protocol To Measure Gene Expression In The Mouse Tibia, Daniel Hoover

Biomedical Engineering

Numerous molecular factors active in bone tissue direct fracture repair and remodeling which can be altered by disease conditions such as Peripheral Arterial Disease (PAD) and Osteoporosis. Methods of molecular biology are commonly applied to investigate the expression and role of these molecular factors. This project presents a robust three-step protocol for examining gene expression in the mouse tibia. The protocol begins with isolating RNA from a flash frozen tibia sample. The isolated RNA is reverse transcribed into cDNA. Finally, PCR is performed to indentify expressed genes. Establishing this protocol will allow further research into the mechanisms of bone remodeling …


Regulation Of A Duplicated Locus: Drosophila Sloppy Paired Is Replete With Functionally Overlapping Enhancers., Miki Fujioka, James B Jaynes Feb 2012

Regulation Of A Duplicated Locus: Drosophila Sloppy Paired Is Replete With Functionally Overlapping Enhancers., Miki Fujioka, James B Jaynes

Department of Biochemistry and Molecular Biology Faculty Papers

In order to investigate regulation and redundancy within the sloppy paired (slp) locus, we analyzed 30 kilobases of DNA encompassing the tandem, coordinately regulated slp1 and slp2 transcription units. We found a remarkable array of stripe enhancers with overlapping activities surrounding the slp1 transcription unit, and, unexpectedly, glial cell enhancers surrounding slp2. The slp stripe regulatory region generates 7 stripes at blastoderm, and later 14 stripes that persist throughout embryogenesis. Phylogenetic analysis among drosophilids suggests that the multiplicity of stripe enhancers did not evolve through recent duplication. Most of the direct integration among cis-regulatory modules appears to be simply additive, …


Structure Of The Atp Synthase Catalytic Complex (F(1)) From Escherichia Coli In An Autoinhibited Conformation., Gino Cingolani, Thomas M Duncan Jun 2011

Structure Of The Atp Synthase Catalytic Complex (F(1)) From Escherichia Coli In An Autoinhibited Conformation., Gino Cingolani, Thomas M Duncan

Department of Biochemistry and Molecular Biology Faculty Papers

ATP synthase is a membrane-bound rotary motor enzyme that is critical for cellular energy metabolism in all kingdoms of life. Despite conservation of its basic structure and function, autoinhibition by one of its rotary stalk subunits occurs in bacteria and chloroplasts but not in mitochondria. The crystal structure of the ATP synthase catalytic complex (F(1)) from Escherichia coli described here reveals the structural basis for this inhibition. The C-terminal domain of subunit ɛ adopts a heretofore unknown, highly extended conformation that inserts deeply into the central cavity of the enzyme and engages both rotor and stator subunits in extensive contacts …


Ribosome Recycling Step In Yeast Cytoplasmic Protein Synthesis Is Catalyzed By Eef3 And Atp., Shinya Kurata, Klaus H Nielsen, Sarah F Mitchell, Jon R Lorsch, Akira Kaji, Hideko Kaji Jun 2010

Ribosome Recycling Step In Yeast Cytoplasmic Protein Synthesis Is Catalyzed By Eef3 And Atp., Shinya Kurata, Klaus H Nielsen, Sarah F Mitchell, Jon R Lorsch, Akira Kaji, Hideko Kaji

Department of Biochemistry and Molecular Biology Faculty Papers

After each round of protein biosynthesis, the posttermination complex (PoTC) consisting of a ribosome, mRNA, and tRNA must be disassembled into its components for a new round of translation. Here, we show that a Saccharomyces cerevisiae model PoTC was disassembled by ATP and eukaryotic elongation factor 3 (eEF3). GTP or ITP functioned with less efficiency and adenosine 5gamma'-(beta,gamma-imido)triphosphate did not function at all. The k(cat) of eEF3 was 1.12 min(-1), which is comparable to that of the in vitro initiation step. The disassembly reaction was inhibited by aminoglycosides and cycloheximide. The subunits formed from the yeast model PoTC remained separated …