Structural Evidence for Ammonia Tunneling across the (βα)8 Barrel of the Imidazole Glycerol Phosphate Synthase Bienzyme Complex
| Autor: | Silke Beismann-Driemeyer, M.Cristina Vega-Fernandez, Alice Douangamath, Reinhard Sterner, Martina Walker, Matthias Wilmanns |
|---|---|
| Rok vydání: | 2002 |
| Předmět: |
Models
Molecular Macromolecular Substances Protein Conformation Stereochemistry Molecular Sequence Data Static Electricity glutamine amidotransferase Crystallography X-Ray Glutaminase activity Structure-Activity Relationship imidazole glycerol phosphate synthase Aminohydrolases Ammonia Structural Biology Thermotoga maritima Amino Acid Sequence ammonia tunnel Purine metabolism Molecular Biology Histidine Glutamine amidotransferase ATP synthase biology Glutaminase (βα)8 barrel Hydrogen Bonding bienzyme complex biology.organism_classification Glutamine Protein Subunits Biochemistry biology.protein X-ray structure Protein Binding |
| Zdroj: | Structure. 10:185-193 |
| ISSN: | 0969-2126 |
| DOI: | 10.1016/s0969-2126(02)00702-5 |
| Popis: | Since reactive ammonia is not available under physiological conditions, glutamine is used as a source for the incorporation of nitrogen in a number of metabolic pathway intermediates. The heterodimeric ImGP synthase that links histidine and purine biosynthesis belongs to the family of glutamine amidotransferases in which the glutaminase activity is coupled with a subsequent synthase activity specific for each member of the enzyme family. Its X-ray structure from the hyperthermophile Thermotoga maritima shows that the glutaminase subunit is associated with the N-terminal face of the (beta alpha)(8) barrel cyclase subunit. The complex reveals a putative tunnel for the transfer of ammonia over a distance of 25 A. Although ammonia tunneling has been reported for glutamine amidotransferases, the ImGP synthase has evolved a novel mechanism, which extends the known functional properties of the versatile (beta alpha)(8) barrel fold. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|