Topic
Mutase
About: Mutase is a research topic. Over the lifetime, 900 publications have been published within this topic receiving 28121 citations.
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Book•
1 Jan 1999
TL;DR: This work has shown that Cobalamin Transport in Bacteria and Regulation of Adenosylcobalamin Biosynthesis in Salmonella typhimurium, and the Role of Corrinoids in Methanogenesis, are regulated by different mechanisms and require different approaches to be understood.
Abstract: CHEMISTRY OF B-12. B-12 History (H. Hogenkamp). X-ray Crystallography of B-12 (B. Krautler & C. Kratky). X-Ray Absorption Spectorscopy of B-12: Structural Changes of Intermediate States (M. Chance). Electronic Structure and Spectra of B-12: From Trans Effects to Protein Conformation I (J. Pratt). Electronic Structure and Spectra of B-12: From Trans Effects to Protein Conformation II (J. Pratt). EPR Spectroscopy of B-12-Dependent Enzymes (G. Gerfen). NMR Spectroscopy of B-12 (K. Brown). Vibrational Spectroscopy of B-12 and Related Compounds (L. Marzilli & S. Hirota). Magnetic Field Dependence of Cobalamin Photochemistry and Enzymes (C. Grissom). Stereospecificity of the Coenzyme B-12 Catalyzed Rearrangements and the Role of Negative Catalysis (J. Retey). Modeling the Structure of Cobalt Corrins by Molecular Mechanics and Molecular Dynamics Methods (H. Marques). B-12 Electrochemistry and Organometallic Electrochemical Synthesis (B. Krautler). BIOCHEMISTRY AND BIOLOGY OF B-12. B-12 and Nutrition (S. Stabler). Inborn Errors of Cobalamin Metabolism (D. Rosenblatt & W. Fenton). Diagnostic and Therapeutic Analogs of Cobalamin (H. Hogenkamp, et al.). Intrinsic Factor and Haptocorrin and Their Receptors (D. Alpers & G. Russell-Jones). Transcobalamin II (S. Rothenberg, et al.). Mammalian Receptors of Vitamin B-12-Binding Proteins (S. Moestrup & P. Verroust). Cobalamin Transport in Bacteria (C. Bradbeer). Biosynthesis of B-12 in the Aerobic Organism Pseudomonas denitrificans (A. Battersby & F. Leeper). B-12 Biosynthesis: The Anaerobic Pathway (A. Scott, et al.). Biosynthesis of the 5-6 Dimethylbenzimidazole Moiety of Cobalamin and of the Other Bases Found in Natural Corrinoids (P. Renz). Regulation of Adenosylcobalamin Biosynthesis in Salmonella typhimurium (J. Semerena). X-ray Crystallography of B-12 Enzymes: Methylmalonyl-CoA Mutase and Methionine Synthase (M. Ludwig & P. Evans). The Acetogenic Corriniod Proteins (S. Ragsdale). The Role of Corrinoids in Methanogenesis (K. Sauer & R. Thauer). Methionine Synthase (R. Matthews). Methylmalonyl-CoA Mutase (R. Banerjee & S. Chowdhury). Ribonucleotide Reductases (M. Fontecave & E. Mulliez). Glutamate Mutase and 2-Methyleneglutarate Mutase (W. Buckel, et al.). Diol Dehydrase and Glycerol Dehydrase (T. Toraya). Ethanolamine Ammonia-Lyase (V. Bandarian & G. Reed). Anomutases (P. Frey). Isobutyryl-CoA Mutase (K. Zerbe-Burkhardt, et al.). Reductive Dehalogenases (G. Wohlfarth & G. Diekert).
707 citations
1 Jan 1982
TL;DR: The final unique stage in the metabolism of L-isoleucine involves the cleavage of 2-methylacetoacetyl-CoA to acetyl- coA and propionyl- CoA and methylmalonyl-Co a (Section 10.4).
Abstract: The final unique stage in the metabolism of L-isoleucine involves the cleavage of 2-methylacetoacetyl-CoA to acetyl-CoA and propionyl-CoA (Section 104) The propionyl-CoA is further metabolized to methylmalonyl-CoA by a biotin-dependent carboxylase and subsequently via succinyl-CoA into the tricarboxylic acid cycle L-Valine is also metabolized ultimately to methylmalonyl-CoA (Section 104), and thus these two branched-chain amino acids form the major precursors of propionyl-CoA and methylmalonyl-CoA Other precursors of propionyl-CoA include methionine, threonine, oddcarbon-number fatty acids and cholesterol The methylmalonyl-CoA produced by propionyl-CoA carboxylase occurs as the D(S)-enantiomer and is racemized to the L(R)-enantiomer by methylmalonyl-CoA racemase L(R)Methylmalonyl-CoA is then metabolized to succinyl-CoA by a vitamin B12-dependent mutase prior to introduction of the modified molecule into the tricarboxylic acid cycle
687 citations
TL;DR: The crystal structure of a 27-kilodalton methylcobalamin-containing fragment of methionine synthase from Escherichia coli was determined at 3.0 A resolution, revealing that the cobalt ligand, His759, and the neighboring residues Asp757 and Ser810, may form a catalytic quartet that modulates the reactivity of the B12 prosthetic group in methionines synthase.
Abstract: The crystal structure of a 27-kilodalton methylcobalamin-containing fragment of methionine synthase from Escherichia coli was determined at 3.0 A resolution. This structure depicts cobalamin-protein interactions and reveals that the corrin macrocycle lies between a helical amino-terminal domain and an alpha/beta carboxyl-terminal domain that is a variant of the Rossmann fold. Methylcobalamin undergoes a conformational change on binding the protein; the dimethylbenzimidazole group, which is coordinated to the cobalt in the free cofactor, moves away from the corrin and is replaced by a histidine contributed by the protein. The sequence Asp-X-His-X-X-Gly, which contains this histidine ligand, is conserved in the adenosylcobalamin-dependent enzymes methylmalonyl-coenzyme A mutase and glutamate mutase, suggesting that displacement of the dimethylbenzimidazole will be a feature common to many cobalamin-binding proteins. Thus the cobalt ligand, His759, and the neighboring residues Asp757 and Ser810, may form a catalytic quartet, Co-His-Asp-Ser, that modulates the reactivity of the B12 prosthetic group in methionine synthase.
582 citations
TL;DR: The histidine-cobalt distance is very long, suggesting that the enzyme positions the histidine in order to weaken the metal-carbon bond of the cofactor and favour the formation of the initial radical species.
461 citations
TL;DR: In this article, the determination of glucose-6-phosphatase from liver was discussed, based on the incubation of the specific substrate with the enzyme and determination of the liberated orthophosphate.
Abstract: This chapter discusses the determination of glucose-6-phosphatase from liver. The assay method is based on the incubation of the specific substrate with the enzyme and determination of the liberated orthophosphate. Attempts to purify the enzyme have been limited by its extreme instability and its insolubility. It appears to be bound to the microsomes. These can be sedimented from isotonic sucrose at 30,000 X g , or agglutinated at pH 5.4. The precipitated microsomes may be washed at this pH to remove phosphoglucomutase. Hexose isomerase, ATPase, AMPase, and a feeble glycerophosphatase are not removed by the washing. Solubilization by means of detergents or bile salts has not been attempted. The enzyme is apparently specific for G-6-P. After removal of the mutase by washing, G-1-P is split not at all, and fructose disappears in the same proportion that inorganic phosphate is liberated from F-6-P. Galactose phosphate and mannose phosphate have not been tested. It has an optimum pH of 6.5 and appears to require no metallic activator. Molybdate and arsenate inhibit to some extent; fluoride gives very inconsistent results.
413 citations
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Performance Metrics
| Year | Papers |
|---|---|
| 2025 | 11 |
| 2024 | 11 |
| 2023 | 18 |
| 2022 | 25 |
| 2021 | 7 |
| 2020 | 11 |