title: Purification and properties of D-ribulokinase and D-xylulokinase from Klebsiella aerogenes.
abstract: The D-ribulokinase and D-xylulokinase of Klebsiella aerogenes were purified to homogeneity from Escherichia coli K12 construct strains that synthesized these enzymes constitutively. The D-ribulokinase, which is encoded in the ribitol operon, is active as a dimer of 60 000 subunit mol.wt., whereas the D-xylulokinase, which is encoded in the D-arabitol operon, is active as a dimer of 54 000 subunit mol.wt. The amino acid compositions and N-terminal sequences of both pentulokinases are reported. The Kapp. values of the enzymes for their D-pentulose substrates were determined, and the D-ribulokinase was shown to have a low-affinity side-specificity for ribitol and D-arabitol. These results are discussed in the context of the evolution of the Klebsiella aerogenes pentitol operons.
mesh_terms: D000596:Amino Acids / Q000032:analysis; D004591:Electrophoresis, Polyacrylamide Gel; D007700:Kinetics; D007711:Klebsiella pneumoniae / Q000201:enzymology*; D008970:Molecular Weight; D010429:Pentoses / Q000302:isolation & purification; D010770:Phosphotransferases / Q000302:isolation & purification*; D017853:Phosphotransferases (Alcohol Group Acceptor); D013379:Substrate Specificity
chemical_list: D000596:Amino Acids; D010429:Pentoses; C100182:ribulose; D010770:Phosphotransferases; D017853:Phosphotransferases (Alcohol Group Acceptor); C032700:xylulokinase; C022551:D-ribulokinase