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Dioxygenases
Dioxygenases are oxidoreductase enzymes. Aerobic life, from simple single-celled bacteria species to complex eukaryotic organisms, has evolved to depend on the oxidizing power of dioxygen in various metabolic pathways. From energetic adenosine triphosphate (ATP) generation to xenobiotic degradation, the use of dioxygen as a biological oxidant is widespread and varied in the exact mechanism of its use. Enzymes employ many different schemes to use dioxygen, and this largely depends on the substrate and reaction at hand. Comparison with monooxygenases In the monooxygenases, only a single atom of dioxygen is incorporated into a substrate with the other being reduced to a water molecule. The dioxygenases () catalyze the oxidation of a substrate without the reduction of one oxygen atom from dioxygen into a water molecule. However, this definition is ambiguous because it does not take into account how many substrates are involved in the reaction. The majority of dioxygenases fully incorp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
2-oxoglutarate (2OG)-dependent Dioxygenases
Alpha-ketoglutarate-dependent hydroxylases are a major class of non-heme iron proteins that catalyse a wide range of reactions. These reactions include hydroxylation reactions, demethylations, ring expansions, ring closures, and desaturations. Functionally, the αKG-dependent hydroxylases are comparable to cytochrome P450 enzymes. Both use O2 and reducing equivalents as cosubstrates and both generate water. Biological function αKG-dependent hydroxylases have diverse roles. In microorganisms such as bacteria, αKG-dependent dioxygenases are involved in many biosynthetic and metabolic pathways; for example, in ''E. coli'', the AlkB enzyme is associated with the repair of damaged DNA. In plants, αKG-dependent dioxygenases are involved in diverse reactions in plant metabolism. These include flavonoid biosynthesis, and ethylene biosyntheses. In mammals and humans, αKG-dependent dioxygenase have functional roles in biosyntheses (e.g. collagen biosynthesis and L-carnitine biosynthe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Catechol Dioxygenase
Catechol dioxygenases are metalloprotein enzymes that carry out the oxidative cleavage of catechols. This class of enzymes incorporate dioxygen into the substrate. Catechol dioxygenases belong to the class of oxidoreductases and have several different substrate specificities, including catechol 1,2-dioxygenase (), catechol 2,3-dioxygenase (), and protocatechuate 3,4-dioxygenase (). The active site of catechol dioxygenases most frequently contains iron, but manganese-containing forms are also known. The ''Pseudomonas putida'' xylE gene, which encodes catechol 2,3-dioxygenase, is often used as a reporter to quantitate gene expression. An example of the reaction carried out by catechol 1,2-dioxygenase is the formation of ''cis,cis''-muconic acid from catechol, shown below. See also * Bioinorganic chemistry * Oxygenase An oxygenase is any enzyme that oxidizes a substrate by transferring the oxygen from molecular oxygen O2 (as in air) to it. The oxygenases form a class of oxi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rieske Protein
Rieske proteins are iron–sulfur protein (ISP) components of cytochrome ''bc''1 complexes and cytochrome b6f complexes and are responsible for electron transfer in some biological systems. John S. Rieske and co-workers first discovered the protein and in 1964 isolated an acetylated form of the bovine mitochondrial protein. In 1979 Trumpower's lab isolated the "oxidation factor" from bovine mitochondria and showed it was a reconstitutively-active form of the Rieske iron-sulfur protein It is a unique Fe-2Scluster in that one of the two Fe atoms is coordinated by two histidine residues rather than two cysteine residues. They have since been found in plants, animals, and bacteria with widely ranging electron reduction potentials from -150 to +400 mV. Biological function Ubiquinol-cytochrome-c reductase (also known as bc1 complex or complex III) is an enzyme complex of bacterial and mitochondrial oxidative phosphorylation systems. It catalyses the oxidation-reduction reaction ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tyrosine
-Tyrosine or tyrosine (symbol Tyr or Y) or 4-hydroxyphenylalanine is one of the 20 standard amino acids that are used by cells to synthesize proteins. It is a non-essential amino acid with a polar side group. The word "tyrosine" is from the Greek ''tyrós'', meaning ''cheese'', as it was first discovered in 1846 by German chemist Justus von Liebig in the protein casein from cheese. It is called tyrosyl when referred to as a functional group or side chain. While tyrosine is generally classified as a Hydrophobe, hydrophobic amino acid, it is more hydrophilic than phenylalanine. It is Genetic code, encoded by the Genetic code#Codons, codons UAC and UAU in messenger RNA. Functions Aside from being a proteinogenic amino acid, tyrosine has a special role by virtue of the phenol functionality. It occurs in proteins that are part of signal transduction processes and functions as a receiver of phosphate groups that are transferred by way of protein kinases. Phosphorylation of the hyd ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jelly Roll Motif
The jelly roll or Swiss roll fold is a protein fold or supersecondary structure composed of eight beta strands arranged in two four-stranded sheets. The name of the structure was introduced by Jane S. Richardson in 1981, reflecting its resemblance to the jelly or Swiss roll cake. The fold is an elaboration on the Greek key motif and is sometimes considered a form of beta barrel. It is very common in viral proteins, particularly viral capsid proteins. Taken together, the jelly roll and Greek key structures comprise around 30% of the all-beta proteins annotated in the Structural Classification of Proteins (SCOP) database. Structure The basic jelly roll structure consists of eight beta strands arranged in two four-stranded antiparallel beta sheets which pack together across a hydrophobic interface here citation... uniprot The strands are traditionally labeled B through I for the historical reason that the first solved structure, of a jelly roll capsid protein from the tomato bu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oxidoreductase
In biochemistry, an oxidoreductase is an enzyme that catalyzes the transfer of electrons from one molecule, the reductant, also called the electron donor, to another, the oxidant, also called the electron acceptor. This group of enzymes usually utilizes NADP+ or NAD+ as cofactors. Transmembrane oxidoreductases create electron transport chains in bacteria, chloroplasts and mitochondria, including respiratory complexes I, II and III. Some others can associate with biological membranes as peripheral membrane proteins or be anchored to the membranes through a single transmembrane helix. in ...
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Cupin Superfamily
The cupin superfamily is a diverse superfamily of proteins named after its conserved barrel domain (''cupa'' being the Latin term for a small barrel). The superfamily includes a wide variety of enzymes as well as non-enzymatic seed storage proteins. Members of the superfamily play a role in allergy, especially seed storage proteins like 7S and 11S globulins, also known as vicilins and legumins, respectively. These proteins can be found at high concentrations in seeds of both mono- and dicotyledonous plants and are an important component of the normal human diet. History Thomas Burr Osborne at the end of the 19th century was the first person to systematically study seed storage proteins by their solubility characteristics. He established 4 classes of proteins: water-soluble albumins; salt soluble globulins: vicilin—typically having sedimentation coefficients, S values (a measure of the protein mass determined by sedimentation equilibrium ultracentrifugation) of about 7 S ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
FAD Reductase (NADH)
FAD reductase (NADH) (, ''NADH-FAD reductase'', ''NADH-dependent FAD reductase'') is an enzyme with systematic name ''FADH2:NAD+ oxidoreductase''. This enzyme catalyses the following chemical reaction A chemical reaction is a process that leads to the IUPAC nomenclature for organic transformations, chemical transformation of one set of chemical substances to another. Classically, chemical reactions encompass changes that only involve the pos ... : FADH2 + NAD+ \rightleftharpoons FAD + NADH + H+ The enzyme from Burkholderia phenoliruptrix has a preference for FAD. References External links * {{Portal bar, Biology, border=no EC 1.5.1 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pseudomonas
''Pseudomonas'' is a genus of Gram-negative, Gammaproteobacteria, belonging to the family Pseudomonadaceae and containing 191 described species. The members of the genus demonstrate a great deal of metabolic diversity and consequently are able to colonize a wide range of niches. Their ease of culture ''in vitro'' and availability of an increasing number of ''Pseudomonas'' strain genome sequences has made the genus an excellent focus for scientific research; the best studied species include ''P. aeruginosa'' in its role as an opportunistic human pathogen, the plant pathogen '' P. syringae'', the soil bacterium '' P. putida'', and the plant growth-promoting ''P. fluorescens, P. lini, P. migulae'', and ''P. graminis''. Because of their widespread occurrence in water and plant seeds such as dicots, the pseudomonads were observed early in the history of microbiology. The generic name ''Pseudomonas'' created for these organisms was defined in rather vague terms by Walter Migula i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ferryl
A transition metal oxo complex is a coordination complex containing an oxo ligand. Formally O2-, an oxo ligand can be bound to one or more metal centers, i.e. it can exist as a terminal or (most commonly) as bridging ligands (Fig. 1). Oxo ligands stabilize high oxidation states of a metal.Nugent, W. A., Mayer, J. M. "Metal-Ligand Multiple Bonds." John Wiley & Sons, New York, 1988. They are also found in several metalloproteins, for example in molybdenum cofactors and in many iron-containing enzymes. One of the earliest synthetic compounds to incorporate an oxo ligand is potassium ferrate (K2FeO4), which was likely prepared by Georg E. Stahl in 1702. Reactivity Olation and acid-base reactions A common reaction exhibited by metal-oxo compounds is olation, the condensation process that converts low molecular weight oxides to polymers with M-O-M linkages. Olation often begins with the deprotonation of a metal-hydroxo complex. It is the basis for mineralization and the precipita ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fe(II)
In chemistry, iron(II) refers to the element iron in its +2 oxidation state. In ionic compounds (salts), such an atom may occur as a separate cation (positive ion) denoted by Fe2+. The adjective ferrous or the prefix ferro- is often used to specify such compounds — as in "ferrous chloride" for iron(II) chloride, . The adjective "ferric" is used instead for iron(III) salts, containing the cation or Fe3+. The word ferrous is derived from the Latin word ''ferrum'' for iron. Iron(II) atoms may also occur as coordination complexes, such as the polymer iron(II) oxalate dihydrate, or ; and organometallic compounds, such as the neutral molecule ferrocene, or . Iron is almost always encountered in the oxidation states 0 (as in the metal), +2, or +3. Solid iron(II) salts are relatively stable in air, but in the presence of air and water they tend to oxidize to iron(III) salts that include hydroxide () or oxide () anions. Iron(II) and life All known forms of life require iron. Man ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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