FRUCTOSE 1,6-BISPHOSPHATE ALDOLASE FROM HUMAN LIVER TISSUE
[ALDOB_HUMAN] Defects in ALDOB are the cause of hereditary fructose intolerance (HFI) [MIM:229600]. HFI is an autosomal recessive disease that results in an inability to metabolize fructose and related sugars. Complete exclusion of fructose results in dramatic recovery; however, if not treated properly, HFI subjects suffer episodes of hypoglycemia, general ill condition, and risk of death the remainder of life.         
Publication Abstract from PubMed
The X-ray crystallographic structure of the human liver isozyme of fructose-1,6-bisphosphate aldolase has been determined by molecular replacement using a tetramer of the human muscle isozyme as a search model. The liver aldolase (B isozyme) crystallized in space group C2, with unit-cell parameters a = 291.1, b = 489.8, c = 103.4 A, alpha = 90, beta = 103.6, gamma = 90 degrees. These large unit-cell parameters result from the presence of 18 subunits in the asymmetric unit: four catalytic tetramers and a dimer from a fifth tetramer positioned on the twofold crystallographic axis. This structure provides further insight into the factors affecting isozyme specificity. It reveals small differences in secondary structure that occur in regions previously determined to be isozyme specific. Two of these regions are at the solvent-exposed enzyme surface away from the active site of the enzyme. The most significant changes are in the flexible C-terminal region of the enzyme, where there is an insertion of an extra alpha-helix. Point mutations of the human liver aldolase are responsible for the disease hereditary fructose intolerance. Sequence information is projected onto the new crystal structure in order to indicate how these mutations bring about reduced enzyme activity and affect structural stability.
The structure of human liver fructose-1,6-bisphosphate aldolase.,Dalby AR, Tolan DR, Littlechild JA Acta Crystallogr D Biol Crystallogr. 2001 Nov;57(Pt 11):1526-33. Epub 2001, Oct 25. PMID:11679716
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.