GH1-family 6-P-β-glucosidases from human microbiome lactic acid bacteria
| Autor: | Hui Li, Kemin Tan, Catherine Hatzos-Skintges, Gyorgy Babnigg, Jessica Bearden, Andrzej Joachimiak, Karolina Michalska |
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| Rok vydání: | 2013 |
| Předmět: |
Crystallography
X-Ray Ligands Streptococcus mutans Phosphotransferase 03 medical and health sciences chemistry.chemical_compound salicin Structural Biology Hydrolase Humans Glycoside hydrolase Phosphoenolpyruvate Sugar Phosphotransferase System 030304 developmental biology chemistry.chemical_classification 0303 health sciences GH1 biology 030302 biochemistry & molecular biology General Medicine 6-P-β-glucosidases biology.organism_classification Research Papers Lactic acid Enzyme chemistry Biochemistry cellobiose gentiobiose biology.protein Metagenome glycoside hydrolases Glucosidases Bacteria Lactobacillus plantarum |
| Zdroj: | Acta Crystallographica Section D: Biological Crystallography |
| ISSN: | 1399-0047 0907-4449 |
| DOI: | 10.1107/s0907444912049608 |
| Popis: | The crystal structures of two 6-P-β-glucosidases from the GH1 family were determined in the apo form and in the presence of a 6′-P-salicin substrate, of the reaction product 6-P-β-glucose and of glucose corresponding to the aglycon molecule. The presence of natural ligands enabled the definition of the structural elements responsible for the recognition and hydrolysis of 6′-P-β-glucosides. In lactic acid bacteria and other bacteria, carbohydrate uptake is mostly governed by phosphoenolpyruvate-dependent phosphotransferase systems (PTSs). PTS-dependent translocation through the cell membrane is coupled with phosphorylation of the incoming sugar. After translocation through the bacterial membrane, the β-glycosidic bond in 6′-P-β-glucoside is cleaved, releasing 6-P-β-glucose and the respective aglycon. This reaction is catalyzed by 6-P-β-glucosidases, which belong to two glycoside hydrolase (GH) families: GH1 and GH4. Here, the high-resolution crystal structures of GH1 6-P-β-glucosidases from Lactobacillus plantarum (LpPbg1) and Streptococcus mutans (SmBgl) and their complexes with ligands are reported. Both enzymes show hydrolytic activity towards 6′-P-β-glucosides. The LpPbg1 structure has been determined in an apo form as well as in a complex with phosphate and a glucose molecule corresponding to the aglycon molecule. The S. mutans homolog contains a sulfate ion in the phosphate-dedicated subcavity. SmBgl was also crystallized in the presence of the reaction product 6-P-β-glucose. For a mutated variant of the S. mutans enzyme (E375Q), the structure of a 6′-P-salicin complex has also been determined. The presence of natural ligands enabled the definition of the structural elements that are responsible for substrate recognition during catalysis. |
| Databáze: | OpenAIRE |
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