Cobalt chelatase (EC 6.6.1.2) is an enzyme that catalyzes the chemical reaction
In enzymology, a Mg2+-importing ATPase (EC 3.6.3.2) is an enzyme that catalyzes the chemical reaction
In enzymology, a butyrate kinase is an enzyme that catalyzes the chemical reaction
In enzymology, a hydroxyethylthiazole kinase is an enzyme that catalyzes the chemical reaction
Bacterial microcompartments (BMCs) are organelle-like structures found in bacteria. They consist of a protein shell that encloses enzymes and other proteins. BMCs are typically about 40–200 nanometers in diameter and are made entirely of proteins. The shell functions like a membrane, as it is selectively permeable. Other protein-based compartments found in bacteria and archaea include encapsulin nanocompartments and gas vesicles.
In molecular biology, acetate kinase (EC 2.7.2.1), which is predominantly found in micro-organisms, facilitates the production of acetyl-CoA by phosphorylating acetate in the presence of ATP and a divalent cation. Short-chain fatty acids (SCFAs) play a major role in carbon cycle and can be utilized as a source of carbon and energy by bacteria. Salmonella typhimurium propionate kinase (StTdcD) catalyzes reversible transfer of the γ-phosphate of ATP to propionate during l-threonine degradation to propionate. Kinetic analysis revealed that StTdcD possesses broad ligand specificity and could be activated by various SCFAs (propionate>acetate≈butyrate), nucleotides (ATP≈GTP>CTP≈TTP; dATP>dGTP>dCTP) and metal ions (Mg2+≈Mn2+>Co2+). Inhibition of StTdcD by tricarboxylic acid (TCA) cycle intermediates such as citrate, succinate, α-ketoglutarate and malate suggests that the enzyme could be under plausible feedback regulation. Crystal structures of StTdcD bound to PO4 (phosphate), AMP, ATP, Ap4 (adenosine tetraphosphate), GMP, GDP, GTP, CMP and CTP revealed that binding of nucleotide mainly involves hydrophobic interactions with the base moiety and could account for the broad biochemical specificity observed between the enzyme and nucleotides. Modelling and site-directed mutagenesis studies suggest Ala88 to be an important residue involved in determining the rate of catalysis with SCFA substrates. Molecular dynamics simulations on monomeric and dimeric forms of StTdcD revealed plausible open and closed states, and also suggested role for dimerization in stabilizing segment 235-290 involved in interfacial interactions and ligand binding. Observation of an ethylene glycol molecule bound sufficiently close to the γ-phosphate in StTdcD complexes with triphosphate nucleotides supports direct in-line phosphoryl transfer. The enzyme is important in the process of glycolysis, enzyme levels being increased in the presence of excess glucose. The growth of a bacterial mutant lacking acetate kinase has been shown to be inhibited by glucose, suggesting that the enzyme is involved in excretion of excess carbohydrate. A related enzyme, butyrate kinase, facilitates the formation of butyryl-CoA by phosphorylating butyrate in the presence of ATP to form butyryl phosphate.
In molecular biology, cob(I)yrinic acid a,c-diamide adenosyltransferase EC 2.5.1.17 is an enzyme which catalyses the conversion of cobalamin into one of its coenzyme forms, adenosylcobalamin. Adenosylcobalamin is required as a cofactor for the activity of certain enzymes. AdoCbl contains an adenosyl moiety liganded to the cobalt ion of cobalamin via a covalent Co-C bond.
Cobalamin biosynthesis is the process by which bacteria and archea make cobalamin, vitamin B12. Many steps are involved in converting aminolevulinic acid via uroporphyrinogen III and adenosylcobyric acid to the final forms in which it is used by enzymes in both the producing organisms and other species, including humans who acquire it through their diet.
5-nitrosalicylate dioxygenase (EC 1.13.11.64, naaB (gene)) is an enzyme with systematic name 5-nitrosalicylate:oxygen 1,2-oxidoreductase (decyclizing). This enzyme catalyses the following chemical reaction
D-glycero-beta-D-manno-heptose-7-phosphate kinase is an enzyme with systematic name ATP:D-glycero-beta-D-manno-heptose 7-phosphate 1-phosphotransferase. This enzyme catalyses the following chemical reaction
Anhydro-N-acetylmuramic acid kinase (EC 2.7.1.170, anhMurNAc kinase, AnmK) is an enzyme with systematic name ATP:1,6-anhydro-N-acetyl-beta-muramate 6-phosphotransferase. This enzyme catalyses the following chemical reaction
UDP-N-acetylglucosamine kinase is an enzyme with systematic name ATP:UDP-N-acetyl-alpha-D-glucosamine 3'-phosphotransferase. This enzyme catalyses the following chemical reaction
Isopentenyl phosphate kinase is an enzyme with systematic name ATP:isopentenyl phosphate phosphotransferase. This enzyme catalyses the following chemical reaction
D-glycero-beta-D-manno-heptose 1-phosphate adenylyltransferase is an enzyme with systematic name ATP:D-glycero-beta-D-manno-heptose 1-phosphate adenylyltransferase. This enzyme catalyses the following chemical reaction
PepB aminopeptidase is an enzyme which catalyses the following chemical reaction:
Oligopeptidase A is an enzyme. This enzyme catalyses the following chemical reaction
Cobyrinate a,c-diamide synthase (EC ), cobyrinic acid a,c-diamide synthetase, CbiA (gene)) is an enzyme which catalyses the chemical reaction
Acetophenone carboxylase (EC 6.4.1.8) is an enzyme with systematic name acetophenone:carbon-dioxide ligase (ADP-forming). This enzyme catalyses the following chemical reaction
The Nicotinamide Ribonucleoside (NR) Uptake Permease (PnuC) Family is a family of transmembrane transporters that is part of the TOG superfamily. Close PnuC homologues are found in a wide range of Gram-negative and Gram-positive bacteria, archaea and eukaryotes.
Methanogens are a group of microorganisms that produce methane as a byproduct of their metabolism. They play an important role in the digestive system of ruminants. The digestive tract of ruminants contains four major parts: rumen, reticulum, omasum and abomasum. The food with saliva first passes to the rumen for breaking into smaller particles and then moves to the reticulum, where the food is broken into further smaller particles. Any indigestible particles are sent back to the rumen for rechewing. The majority of anaerobic microbes assisting the cellulose breakdown occupy the rumen and initiate the fermentation process. The animal absorbs the fatty acids, vitamins and nutrient content on passing the partially digested food from the rumen to the omasum. This decreases the pH level and initiates the release of enzymes for further breakdown of the food which later passes to the abomasum to absorb remaining nutrients before excretion. This process takes about 9–12 hours.
