Mammalian hexokinase 1: Evolutionary conservation and structure to function analysis

• Published in: Genomics (San Diego, Calif.) Vol. 11; no. 4; pp. 1014 - 1024
• Main Authors: Griffin, L.D., Gelb, B.D., Wheeler, D.A., Davison, D., Adams, V., McCabe, E.R.B.
• Format: Journal Article
• Language: English
• Published: San Diego, CA Elsevier Inc 01.12.1991; Elsevier
• Subjects: Amino Acid Sequence; Animals; Binding Sites; Biological and medical sciences; Biological Evolution; Cattle; Cloning, Molecular; Fundamental and applied biological sciences. Psychology; Genes. Genome; Hexokinase - chemistry; Hexokinase - genetics; Hexokinase - metabolism; Humans; Isoenzymes - chemistry; Isoenzymes - genetics; Isoenzymes - metabolism; Molecular and cellular biology; Molecular genetics; Molecular Sequence Data; Phylogeny; Rats; Sequence Homology, Nucleic Acid; Structure-Activity Relationship; Nucleotide sequence; Enzyme; Isozyme; Ox; Homology; Phylogeny; Structure function relationship; Hexokinase; Molecular evolution; Vertebrata; Conserved sequence; Mammalia; Chromosome DNA; Artiodactyla; Molecular cloning; Ungulata
• ISSN: 0888-7543; 1089-8646
• DOI: 10.1016/0888-7543(91)90027-C

We have amplified and sequenced the complete coding region of bovine hexokinase isoenzyme 1 (HK1) from brain RNA with PCR primers selected for sequence conservation. The sequence information was analyzed to evaluate the evolutionary and structure-function relationships among the mammalian and yeast HK isoenzymes. Structure to function analysis identified an unduplicated, invariant N-terminal domain involved in HK1 outer mitochondrial membrane targeting, as well as putative carbohydrate and nucleotide-binding sites in the regulatory and catalytic halves of HK1 essential to enzyme function. The ATP-binding site in the catalytic half of the HK1 protein resembles nucleotide-binding regions from protein kinases, with the single amino acid replacement (lysine to glutamate) in the ATP-binding site of the amino half explaining the loss of HK1 catalytic function in the regulatory domain. Sequence comparisons suggest that the 50-kDa mammalian and yeast glucokinases arose separately in evolution. In addition to providing valuable phylogenetic and structure-function insights, this work provides an efficient strategy for rapid cloning and sequencing of the coding regions for other HKs and related proteins.