Nucleotide sequence of thearaDgene ofEscherichia coliK12 encoding the L-ribulose 5-phosphate 4-epimerase
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چکیده
منابع مشابه
L-ribulose-5-phosphate 4-epimerase from Aerobacter aerogenes.
The mechanism of L-ribulose 5-phosphate 4-epimerase of Aerobacfer aerogenes has been investigated by determining the kinetic isotope effect (KT/KH) for the epimerization of D-[4-T]xylulose 5-phosphate in the presence of D-[l-14C]xylulose 5-phosphate. The ratio of T:14C was determined for the isolated L-ribulose derived from aliquots of an epimerization reaction mixture during its progress towar...
متن کاملCrystalline L-ribulose 5-phosphate 4-epimerase from Escherichia coli.
L-Ribulose 5-phosphate 4-epimerase has been crystallized from L-arabinose-induced cells of Escherichia coli B/r strain F’ araB-24/araB-24 after a 40-fold purification. The enzyme is homogeneous in the ultracentrifuge and 98% pure by acrylamide gel disc electrophoresis. The molecular weight determined by sedimentation equilibrium is 1.03 f 0.01 X 105. The enzyme is free of D-ribulose 5-phosphate...
متن کاملL-Arabinose-sensitive, L-ribulose 5-phosphate 4-epimerase-deficient mutants of Escherichia coli.
Englesberg, E. (University of Pittsburgh, Pittsburgh, Pa.), R L. Anderson, R. Weinberg, N. Lee, P. Hoffee, G. Huttenhauer, and H. Boyer. l-Arabinose-sensitive, l-ribulose 5-phosphate 4-epimerase-deficient mutants of Escherichia coli. J. Bacteriol. 84:137-146. 1962-l-Arabinose-negative mutants of Escherichia coli B/r, ara-53 and ara-139, are deficient in the enzyme l-ribulose 5-phosphate 4-epime...
متن کاملRole of metal ions in the reaction catalyzed by L-ribulose-5-phosphate 4-epimerase.
H97N, H95N, and Y229F mutants of L-ribulose-5-phosphate 4-epimerase had 10, 1, and 0.1%, respectively, of the activity of the wild-type (WT) enzyme when activated by Zn(2+), the physiological activator. Co(2+) and Mn(2+) replaced Zn(2+) in Y229F and WT enzymes, although less effectively with the His mutants, while Mg(2+) was a poorly bound, weak activator. None of the other eight tyrosines muta...
متن کامل13C and deuterium isotope effects suggest an aldol cleavage mechanism for L-ribulose-5-phosphate 4-epimerase.
On the basis of (13)C and deuterium isotope effects, L-ribulose-5-phosphate 4-epimerase catalyzes the epimerization of L-ribulose 5-phosphate to D-xylulose 5-phosphate by an aldol cleavage to the enediolate of dihydroxyacetone and glycolaldehyde phosphate, followed by rotation of the aldehyde group and condensation to the epimer at C-4. With the wild-type enzyme, (13)C isotope effects were 1.85...
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ژورنال
عنوان ژورنال: Nucleic Acids Research
سال: 1990
ISSN: 0305-1048,1362-4962
DOI: 10.1093/nar/18.22.6722