One of the most interesting and perhaps best-studied plant bacterial interactions is between rhizobial species and economically important leguminous plants (soybean, alfalfa, beans, peas, etc.). Rhizobia are generally described as root-nodule-forming nitrogen-fixing symbionts belonging to one of five species, Rhizobium, Bradyrhizobium, Sinorhizobium, Azorhizobium, and Mesorhizobium. The S. meliloti (Sinorhizobium meliloti) genome consists of a circular chromosome and two large circular elements (mega plasmids), one of which is essential for growth and Quorum-sensing (Ref.1 & 2). In this Gram-negative bacterium the metabolism of amino acids like Glycine is indispensable for functioning of one-carbon metabolism and for the establishment of a fully effective,[..]
T. tengcongensis (Thermoanaerobacter tengcongensis) is a rod-shaped, Gram-negative, anaerobic eubacterium that metabolizes sugars as the principal source of energy and carbon source, and gains energy anaerobically by Sulfur respiration. T. tengcongensis has a complete collection of genes involved in most of the amino acid biosynthetic pathways for Threonine, Valine, Leucine, Histidine, Phenylalanine/Tyrosine, Tryptophan, Arginine and Methionine. However, it lacks a few key genes such as Threonine Dehydratase for Isoleucine biosynthesis and Ornithine Cyclodeaminase for Proline biosynthesis. For nucleotide metabolism, it also has a complete set of genes for Purine biosynthesis, Purine salvage, and Pyrimidine biosynthesis pathways (Ref.1). In the direction of L-Threonine[..]
The CD1 (Thymocyte Antigen CD1) antigen presentation system presents lipid and glycolipid antigens to effector T-Cells, which have diverse roles in Antimicrobial responses, Antitumor immunity and in regulating the balance between Tolerance and Autoimmunity. CD1, a conserved family of MHC (Major Histocompatibility Complex)-like glycoproteins in mammals, specializes in capturing lipid rather than peptide antigen for presentation to T-lymphocytes (Ref.1). The CD1 family consists of five isoforms of non-polymorphic lipid antigen-presenting molecules, which are classified into two groups: Group-I (CD1A, CD1B, CD1C, and CD1E) and Group-II (CD1D), based on similarities between nucleotide and amino acid sequences. Topologically, they resemble the classical peptide[..]
Hepatitis-C Virus (HCV) belongs to the Flaviviridae family and is the leading cause of chronic liver disease globally. It is estimated to infect about 170 million people around the world (WHO, 1997). Chronic HCV infection frequently leads to liver fibrosis and cirrhosis, and is associated with the occurrence of hepatocellular carcinoma. Acute infection occurs in only a few patients. In most cases the virus results in chronic infection taking 10–20 years before the emergence of liver disease, which is often accompanied by only mild or vague symptoms. Despite the seemingly benign onset of the disease, a significant number of patients with chronic hepatitis develop cirrhosis and its complications.HCV infects only humans and chimpanzees; there are no small-animal[..]
ABA (Abscisic Acid) is a plant hormone that plays important role during many phases of the plant life cycle, including seed development and dormancy, embryo maturation, cell division and elongation, and in plant responses to various environmental stresses such as drought, salinity, cold, pathogen attack and UV radiation. However, despite the name, it does not appear to control Abscission directly; the presence of ABA in Abscising organs reflects its role in promoting senescence and/or stress responses, the processes preceding Abscission. ABA is a sesquiterpenoid (C15H20O4) with one asymmetric, optically active Carbon atom at C-1'f. The naturally occurring form is S-(+)-ABA; the side chain of ABA is by definition 2-cis,-4-trans. Trans, trans-ABA is biologically[..]
B. melitensis (Brucella melitensis) is a Gram-negative, aerobic, facultative intracellular bacterial pathogen that causes abortion in goats and sheep and Malta fever in humans. Species in the genus Brucella are the etiological agents of Brucellosis, a zoonotic disease endemic in many areas of the world, characterized by chronic infections in animals leading to abortion and infertility, and a systemic, febrile illness in humans. Brucella is facultative intracellular pathogens that enter the host through mucosal surfaces and are able to survive inside macrophages (Ref.1 & 2). The presence of S-LPS (Smooth Lipopolysaccharide) is an important virulence factor of these organisms. The role of the O-side chain or O-antigen of S-LPS in the survival of Brucella has not been[..]
Species in the genus Brucella are the etiological agents of Brucellosis, a zoonotic disease endemic in many areas of the world, characterized by chronic infections in animals leading to abortion and infertility, and a systemic, febrile illness in humans. Brucella is facultative intracellular pathogens that enter the host through mucosal surfaces and are able to survive inside macrophages. B. suis (Brucella suis) is the first Gram-negative pathogenic organism weaponized as a potential bioterrorism agent (Ref.1). The presence of S-LPS (Smooth Lipopolysaccharide) is an important virulence factor of these organisms. The role of the O-side chain or O-antigen of S-LPS in the survival of Brucella has not been clearly defined; however it might provide a protective mechanism in[..]
The GAs (Gibberellic Acids or Gibberellins) phytohormones play important roles in plant growth and development, promoting seed germination, elongation growth and reproductive development. GA is important for processes including seed germination, stem growth, and flower and fruit development. Gibberellins are modified in the endoplasmic reticulum and cytosol until they reach their biologically-active form. The gibberellins are named GA1 through GAn in order of discovery. Gibberellic acid, which was the first gibberellin to be structurally characterized, is GA3. There are currently 136 GAs identified from plants, fungi and bacteria.GAs is widespread and so far ubiquitous in flowering (Angiosperms) and non-flowering (Gymnosperms) plants as well as ferns. GA mediates[..]
Rhizobium, Bradyrhizobium, Mesorhizobium, Sinorhizobium, and Azorhizobium-collectively known as rhizobia, are Gram-negative, nitrogen-fixing bacteria of agronomic importance because they perform nitrogen-fixing symbioses with leguminous plants (soybean, alfalfa, beans, peas, etc). The metabolism of amino acids like Glycine is indispensable for functioning of one-carbon metabolism and for the establishment of a fully effective, nitrogen-fixing root nodule symbiosis in M. loti (Mesorhizobium loti). Glycine acts as a source of other vital amino acids like L-Serine and L-Threonine. It also contributes to the one-carbon pool, to formation of Glutathione, to Purine nucleotides, and to Porphyrins. Purine Metabolism may also form a source of Glycine. Direct routes of Glycine[..]
R. baltica (Rhodopirellula baltica) is a marine, aerobic, heterotrophic representative of the globally distributed and environmentally important bacterial order Planctomycetales. They catalyze important transformations in global carbon and nitrogen cycles. From a phylogenetic perspective the order Planctomycetales forms an independent, monophyletic phylum of the domain Bacteria. These are thought to be the deepest branching bacterial phylum. Planctomycetes are unique in many other respects. Their cell walls do not contain peptidoglycan, the main structural polymer of most members of the domain Bacteria. They show a unique cell compartmentalization in which a single membrane separates a peripheral ribosome-free paryphoplasm from the inner riboplasm (pirellulosome).[..]
Sterols are a structurally conserved class of lipids that play multifaceted roles in Eukaryotes, serving as essential components of Cell membranes and precursors to Steroid hormones. Characterized by a –OH group on the C3 of the Steroid nucleus, Sterols represent the most abundant type of Steroids in Vertebrates as well as in Plants. In Vertebrates, Cholesterol is by far the major Sterol, whereas a mixture of various Sterols is present in higher plants. The major Sterol is typically Sitosterol, followed by Campesterol, Stigmasterol, and various minor sterols like Isofucosterol, Brassicasterol and Cholesterol. Functional roles for the Campesterol-derived BRs (Brassinosteroids) are established for integrating light signals in the regulation of postembryonic plant[..]
Stmn1 (Stathmin-1) also referred to as Op18 (Oncoprotein-18) is a major regulator of microtubule dynamics. It is an evolutionarily well conserved 17 kDa cytoplasmic phosphoprotein that is highly expressed in a wide variety of cancers and its high abundance seems to be necessary for the maintenance of the transformed phenotypes. Breast cancers exhibit high levels of Stmn1 and may be resistant to anti-microtubule agents. Stmn1 destabilizes microtubule polymers of Alpha and Beta-Tubulin subunits, by promoting catastrophes that ultimately results in deregulation of cell cycle, hampering cell survival (Ref.1). One of the key properties of microtubules is that of ‘dynamic instability’. Dynamic instability comprises the continuous switching between catastrophes[..]
