Download MendeleyGH1-family 6-P-beta-glucosidases from human microbiome lactic acid bacteria.
Michalska, K., Tan, K., Li, H., Hatzos-Skintges, C., Bearden, J., Babnigg, G., Joachimiak, A.(2013) Acta Crystallogr D Biol Crystallogr 69: 451-463
- PubMed: 23519420
- DOI: https://doi.org/10.1107/S0907444912049608
- Primary Citation of Related Structures:
3QOM, 4F66, 4F79, 4GPN, 4GZE - PubMed Abstract:
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.
Organizational Affiliation:
Midwest Center for Structural Genomics, Biosciences Division, Argonne National Laboratory, Argonne, Illinois, USA.
