Structural and Biochemical Studies of TIGAR (TP53-induced Glycolysis and Apoptosis Regulator)
Activation of the p53 tumor suppressor by cellular stress leads to variable responses ranging from growth inhibition to apoptosis. TIGAR is a novel p53-inducible gene that inhibits glycolysis by reducing cellular levels of fructose-2,6-bisphosphate, an activator of glycolysis and inhibitor of gluconeogenesis. Here we describe structural and biochemical studies of TIGAR from Danio rerio. The overall structure forms a histidine phosphatase fold with a phosphate molecule coordinated to the catalytic histidine residue and a second phosphate molecule in a position not observed in other phosphatases. The recombinant human and zebra fish enzymes hydrolyze fructose-2,6-bisphosphate as well as fructose-1,6-bisphosphate but not fructose 6-phosphate in vitro. The TIGAR active site is open and positively charged, consistent with its enzymatic function as bisphosphatase. The closest related structures are the bacterial broad specificity phosphatase PhoE and the fructose-2,6-bisphosphatase domain of the bifunctional 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase. The structural comparison shows that TIGAR combines an accessible active site as observed in PhoE with a charged substrate-binding pocket as seen in the fructose-2,6-bisphosphatase domain of the bifunctional enzyme.
- Research Organization:
- Brookhaven National Lab. (BNL), Upton, NY (United States). National Synchrotron Light Source
- Sponsoring Organization:
- Doe - Office Of Science
- DOE Contract Number:
- DE-AC02-98CH10886
- OSTI ID:
- 980490
- Report Number(s):
- BNL-93408-2010-JA; JBCHA3; TRN: US201015%%1875
- Journal Information:
- Journal of Biological Chemistry, Vol. 284; ISSN 0021-9258
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
99 GENERAL AND MISCELLANEOUS//MATHEMATICS, COMPUTING, AND INFORMATION SCIENCE
APOPTOSIS
ENZYMES
FRUCTOSE
FUNCTIONS
GENES
GLYCOLYSIS
GROWTH
HISTIDINE
HUMAN POPULATIONS
IN VITRO
INHIBITION
LEVELS
MOLECULES
NEOPLASMS
PHOSPHATASES
PHOSPHATES
RESIDUES
SPECIFICITY
WELLS
national synchrotron light source