Human hexokinase: sequences of amino- and carboxyl-terminal halves are homologous.
cDNA clones encoding human hexokinase have been isolated from an adult kidney library. Analysis of this 917 amino acid protein (Mr = 102,519) indicates that the sequences of the NH2- and COOH-terminal halves, corresponding to the regulatory and catalytic domains, respectively, are homologous; and that eukaryotic hexokinases evolved by duplication of a gene encoding a protein of 450 amino acids. The COOH-terminal half of the protein created by this gene duplication retained the glucose binding site and glucose phosphorylating activity while the substrate binding sites of the NH2-terminal half evolved into a new allosteric effector site.
Nishi
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S
Howard Hughes Medical Institute, Department of Biochemistry, University of Chicago, IL 60637.
Seino
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S
Bell
G I
GI
D000494:Allosteric Regulation; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001665:Binding Sites; D002384:Catalysis; D004247:DNA / Q000235:genetics; D015342:DNA Probes; D005947:Glucose / Q000378:metabolism; D006593:Hexokinase / Q000235:genetics*; D006801:Humans; D007668:Kidney / Q000032:analysis; D008969:Molecular Sequence Data; D010766:Phosphorylation; D051381:Rats; D012689:Sequence Homology, Nucleic Acid
D015342:DNA Probes; D004247:DNA; D006593:Hexokinase; D005947:Glucose