Fructose 1,6-bisphosphatase
The enzyme fructose bisphosphatase (EC 3.1.3.11; systematic name D-fructose-1,6-bisphosphate 1-phosphohydrolase) catalyses the conversion of fructose-1,6-bisphosphate to fructose 6-phosphate in gluconeogenesis and the Calvin cycle, which are both anabolic pathways:
- D-fructose 1,6-bisphosphate + H2O = D-fructose 6-phosphate + phosphate
| fructose-1,6-bisphosphatase 1 | |||||||
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Fructose-1,6-bisphosphatase and its fructose 2,6-bisphosphate complex. Rendered from PDB 3FBP. | |||||||
| Identifiers | |||||||
| Symbol | FBP1 | ||||||
| Alt. symbols | FBP | ||||||
| NCBI gene | 2203 | ||||||
| HGNC | 3606 | ||||||
| OMIM | 229700 | ||||||
| RefSeq | NM_000507 | ||||||
| UniProt | P09467 | ||||||
| Other data | |||||||
| EC number | 3.1.3.11 | ||||||
| Locus | Chr. 9 q22.3 | ||||||
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| Fructose-1-6-bisphosphatase | |||||||||
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crystal structure of rabbit liver fructose-1,6-bisphosphatase at 2.3 angstrom resolution | |||||||||
| Identifiers | |||||||||
| Symbol | FBPase | ||||||||
| Pfam | PF00316 | ||||||||
| Pfam clan | CL0171 | ||||||||
| InterPro | IPR000146 | ||||||||
| PROSITE | PDOC00114 | ||||||||
| SCOP2 | 1frp / SCOPe / SUPFAM | ||||||||
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| Firmicute fructose-1,6-bisphosphatase | |||||||||
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| Identifiers | |||||||||
| Symbol | FBPase_2 | ||||||||
| Pfam | PF06874 | ||||||||
| Pfam clan | CL0163 | ||||||||
| InterPro | IPR009164 | ||||||||
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| Fructose-1,6-bisphosphatase | |||||||||
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crystal structure of fructose-1,6-bisphosphatase | |||||||||
| Identifiers | |||||||||
| Symbol | FBPase_3 | ||||||||
| Pfam | PF01950 | ||||||||
| InterPro | IPR002803 | ||||||||
| SCOP2 | 1umg / SCOPe / SUPFAM | ||||||||
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Phosphofructokinase (EC 2.7.1.11) catalyses the reverse conversion of fructose 6-phosphate to fructose-1,6-bisphosphate, but this is not just the reverse reaction, because the co-substrates are different (and so thermodynamic requirements are not violated). The two enzymes each catalyse the conversion in one direction only, and are regulated by metabolites such as fructose 2,6-bisphosphate so that high activity of one of them is accompanied by low activity of the other. More specifically, fructose 2,6-bisphosphate allosterically inhibits fructose 1,6-bisphosphatase, but activates phosphofructokinase-I. Fructose 1,6-bisphosphatase is involved in many different metabolic pathways and found in most organisms. FBPase requires metal ions for catalysis (Mg2+ and Mn2+ being preferred) and the enzyme is potently inhibited by Li+.