3AHI
H320A mutant of Phosphoketolase from Bifidobacterium Breve complexed with acetyl thiamine diphosphate
Summary for 3AHI
| Entry DOI | 10.2210/pdb3ahi/pdb |
| Related | 3AHC 3AHD 3AHE 3AHF 3AHG 3AHH 3AHJ |
| Descriptor | Xylulose 5-phosphate/fructose 6-phosphate phosphoketolase, MAGNESIUM ION, 2-ACETYL-THIAMINE DIPHOSPHATE, ... (6 entities in total) |
| Functional Keywords | thiamine diphosphate-dependent enzyme, alpha-beta fold, homodimer, acetyl thiamine diphosphate, lyase |
| Biological source | Bifidobacterium breve |
| Total number of polymer chains | 1 |
| Total formula weight | 96031.15 |
| Authors | Suzuki, R.,Katayama, T.,Kim, B.-J.,Wakagi, T.,Shoun, H.,Ashida, H.,Yamamoto, K.,Fushinobu, S. (deposition date: 2010-04-22, release date: 2010-08-25, Last modification date: 2023-11-01) |
| Primary citation | Suzuki, R.,Katayama, T.,Kim, B.-J.,Wakagi, T.,Shoun, H.,Ashida, H.,Yamamoto, K.,Fushinobu, S. Crystal Structures of phosphoketolase: thiamine diphosphate-dependent dehydration mechanism J.Biol.Chem., 285:34279-34287, 2010 Cited by PubMed Abstract: Thiamine diphosphate (ThDP)-dependent enzymes are ubiquitously present in all organisms and catalyze essential reactions in various metabolic pathways. ThDP-dependent phosphoketolase plays key roles in the central metabolism of heterofermentative bacteria and in the pentose catabolism of various microbes. In particular, bifidobacteria, representatives of beneficial commensal bacteria, have an effective glycolytic pathway called bifid shunt in which 2.5 mol of ATP are produced per glucose. Phosphoketolase catalyzes two steps in the bifid shunt because of its dual-substrate specificity; they are phosphorolytic cleavage of fructose 6-phosphate or xylulose 5-phosphate to produce aldose phosphate, acetyl phosphate, and H(2)O. The phosphoketolase reaction is different from other well studied ThDP-dependent enzymes because it involves a dehydration step. Although phosphoketolase was discovered more than 50 years ago, its three-dimensional structure remains unclear. In this study we report the crystal structures of xylulose 5-phosphate/fructose 6-phosphate phosphoketolase from Bifidobacterium breve. The structures of the two intermediates before and after dehydration (α,β-dihydroxyethyl ThDP and 2-acetyl-ThDP) and complex with inorganic phosphate give an insight into the mechanism of each step of the enzymatic reaction. PubMed: 20739284DOI: 10.1074/jbc.M110.156281 PDB entries with the same primary citation |
| Experimental method | X-RAY DIFFRACTION (2.1 Å) |
Structure validation
Download full validation report
