Mutagenic and chemical analyses provide new insight into enzyme activation and mechanism of the type 2 iron-sulfur l-serine dehydratase from Legionella pneumophila

2016 ◽  
Vol 596 ◽  
pp. 108-117 ◽  
Author(s):  
Xiao Lan Xu ◽  
Gregory A. Grant
Keyword(s):  
Legionella Pneumophila ◽  
Enzyme Activation ◽  
Chemical Analyses ◽  
Iron Sulfur ◽  
Serine Dehydratase ◽  
Insight Into

scholarly journals Rab1-AMPylation by Legionella DrrA is allosterically activated by Rab1

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Jiqing Du ◽  
Marie-Kristin von Wrisberg ◽  
Burak Gulen ◽  
Matthias Stahl ◽  
Christian Pett ◽  
...  
Keyword(s):  
Legionella Pneumophila ◽  
Adenosine Monophosphate ◽  
Vesicular Trafficking ◽  
Bacterial Protein ◽  
Post Translational Modification ◽  
Allosteric Control ◽  
Rab Protein ◽  
Biochemical Characterisation ◽  
A Site ◽  
Insight Into

AbstractLegionella pneumophila infects eukaryotic cells by forming a replicative organelle – the Legionella containing vacuole. During this process, the bacterial protein DrrA/SidM is secreted and manipulates the activity and post-translational modification (PTM) states of the vesicular trafficking regulator Rab1. As a result, Rab1 is modified with an adenosine monophosphate (AMP), and this process is referred to as AMPylation. Here, we use a chemical approach to stabilise low-affinity Rab:DrrA complexes in a site-specific manner to gain insight into the molecular basis of the interaction between the Rab protein and the AMPylation domain of DrrA. The crystal structure of the Rab:DrrA complex reveals a previously unknown non-conventional Rab-binding site (NC-RBS). Biochemical characterisation demonstrates allosteric stimulation of the AMPylation activity of DrrA via Rab binding to the NC-RBS. We speculate that allosteric control of DrrA could in principle prevent random and potentially cytotoxic AMPylation in the host, thereby perhaps ensuring efficient infection by Legionella.

Insight Into The Molecular Basis Of The Anti‑Hyperglycemic Activity Of Ra‑3 In Type 2 Diabetic Rats And Its Cardioprotective Potential In Cultured Cardiomyoblasts

Metabolism ◽  
2021 ◽  
Vol 116 ◽  
pp. 154646
Author(s):  
R.A. Mosa ◽  
S.E. Mabhida ◽  
N.F. Sangweni ◽  
P.V. Dludla ◽  
A.R. Opoku ◽  
...  
Keyword(s):  
Molecular Basis ◽  
Diabetic Rats ◽  
Type 2 Diabetic ◽  
Insight Into

scholarly journals Brain sonography insight into the midbrain and basal ganglia in myotonic dystrophy type 2

2015 ◽  
Vol 357 ◽  
pp. e343
Author(s):  
V. Rakocevic-Stojanovic ◽  
S. Peric ◽  
D. Savic-Pavicevic ◽  
J. Pesovic ◽  
D. Lavrnic ◽  
...  
Keyword(s):  
Basal Ganglia ◽  
Myotonic Dystrophy ◽  
Myotonic Dystrophy Type ◽  
Myotonic Dystrophy Type 2 ◽  
Brain Sonography ◽  
Insight Into

scholarly journals An insight into antidiabetic properties of six medicinal and edible mushrooms: Inhibition of α-amylase and α-glucosidase linked to type-2 diabetes

2019 ◽  
Vol 120 ◽  
pp. 100-103 ◽  
Author(s):  
D. Stojkovic ◽  
M. Smiljkovic ◽  
A. Ciric ◽  
J. Glamoclija ◽  
L. Van Griensven ◽  
...  
Keyword(s):  
Type 2 Diabetes ◽  
Edible Mushrooms ◽  
Insight Into

scholarly journals Using a Chemical Genetic Screen to Enhance Our Understanding of the Antimicrobial Properties of Gallium against Escherichia coli

Genes ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 34 ◽  
Author(s):  
Natalie Gugala ◽  
Kate Chatfield-Reed ◽  
Raymond J. Turner ◽  
Gordon Chua
Keyword(s):  
Escherichia Coli ◽  
Cell Envelope ◽  
Antimicrobial Properties ◽  
Iron Sulfur Cluster ◽  
Nucleotide Biosynthesis ◽  
E Coli ◽  
Chemical Genetic ◽  
Iron Sulfur ◽  
Insight Into ◽  
Mutant Collection

The diagnostic and therapeutic agent gallium offers multiple clinical and commercial uses including the treatment of cancer and the localization of tumors, among others. Further, this metal has been proven to be an effective antimicrobial agent against a number of microbes. Despite the latter, the fundamental mechanisms of gallium action have yet to be fully identified and understood. To further the development of this antimicrobial, it is imperative that we understand the mechanisms by which gallium interacts with cells. As a result, we screened the Escherichia coli Keio mutant collection as a means of identifying the genes that are implicated in prolonged gallium toxicity or resistance and mapped their biological processes to their respective cellular system. We discovered that the deletion of genes functioning in response to oxidative stress, DNA or iron–sulfur cluster repair, and nucleotide biosynthesis were sensitive to gallium, while Ga resistance comprised of genes involved in iron/siderophore import, amino acid biosynthesis and cell envelope maintenance. Altogether, our explanations of these findings offer further insight into the mechanisms of gallium toxicity and resistance in E. coli.

Circadian rhythms of biliary protein and lipid excretion in rats

1990 ◽  
Vol 258 (5) ◽  
pp. G653-G659 ◽  
Author(s):  
A. Nakano ◽  
P. S. Tietz ◽  
N. F. LaRusso
Keyword(s):  
Circadian Rhythms ◽  
Membrane Proteins ◽  
Biliary Secretion ◽  
Canalicular Membrane ◽  
Nocturnal Feeding ◽  
Transmembrane Flux ◽  
Insight Into ◽  
Lysosomal Proteins

To gain insight into the mechanisms by which hepatocytes release lipids and proteins into bile, we studied extended, steady-state secretion of bile, lipids, and lysosomal and canalicular membrane proteins in freely moving, unanesthetized rats with chronic bile fistulas. We found circadian rhythms of biliary secretion for all measured constituents. In the basal state (nocturnal feeding), two distinct secretory patterns emerged: type 1, characterized by a peak at midnight and a nadir at noon; and type 2, characterized by a peak at 8 A.M. and a nadir at 8 P.M. We observed parallel, type 1 circadian rhythms of excretion for bile, biliary lipids (bile acid, cholesterol, phospholipid), and a canalicular membrane enzyme (alkaline phosphodiesterase I). In contrast, a type 2 circadian rhythm was observed for the outputs of two lysosomal enzymes. Hepatic lysosomal enzyme concentrations and the number of pericanalicular lysosomes decreased (P less than 0.05) by 15 and 35%, respectively, at the nadir of their biliary output relative to the time of their peak outputs. In response to daytime feeding, major shifts in the circadian rhythms of excretion of biliary constituents occurred such that secretion of bile, lipids, and the canalicular membrane protein adopted a type 2-like rhythm, whereas the biliary secretion of the lysosomal proteins exhibited a type 1-like pattern. These results indicate that bile flow and biliary excretion of individual lipids and proteins exhibit distinct circadian rhythms that are altered by feeding. Secretory events at the canaliculus that depend on the transmembrane flux of bile acids, such as water and lipid movement or the solubilization of membrane proteins, display a common rhythm.(ABSTRACT TRUNCATED AT 250 WORDS)

Assessment of cardiovascular risk in type 2 diabetes patients by insight into radial pulse wave harmonic index

2019 ◽  
Vol 228 (1) ◽  
Author(s):  
Kuo‐Meng Liao ◽  
Chi‐Wei Chang ◽  
Sheng‐Hung Wang ◽  
Yi‐Ting Chang ◽  
Ying‐Chun Chen ◽  
...  
Keyword(s):  
Type 2 Diabetes ◽  
Cardiovascular Risk ◽  
Pulse Wave ◽  
Radial Pulse ◽  
Harmonic Index ◽  
Insight Into ◽  
Diabetes Patients
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