Hexokinase: gene structure and mutations.
Hexokinase (HK) deficiency is a rare red cell enzyme deficiency associated with hereditary non-spherocytic haemolytic anaemia; to date, only 17 affected families have been reported. Human HK has four major isozymes, each of which is encoded by a separate gene. Recent studies have shown that both ubiquitously expressed type I HK (HK-I) and erythroid-specific HK-R are expressed in erythrocytes, and that these isozymes are encoded by the single HK-I gene. The human HK-I gene has 19 exons, the HK-I and HK-R transcripts being produced by using two distinct promoters. Thus, the first and second exons are specifically utilized for the erythroid-specific HK-R and ubiquitously expressed HK-I isozymes respectively. So far, only two HK variants have been analysed at the molecular level. Since the human HK-I crystal structure has recently been elucidated, the molecular analysis of the HK variants will be useful for discussing the structure-function relationship of the enzyme.
Department of Biochemistry, Nihon University School of Medicine, Tokyo, Japan.
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D000595:Amino Acid Sequence; D000746:Anemia, Hemolytic, Congenital Nonspherocytic / Q000201:enzymology / Q000235:genetics; D004912:Erythrocytes / Q000201:enzymology; D005091:Exons; D006593:Hexokinase / Q000737:chemistry / Q000172:deficiency / Q000235:genetics*; D006801:Humans; D007527:Isoenzymes / Q000737:chemistry / Q000172:deficiency / Q000235:genetics; D009154:Mutation
D007527:Isoenzymes; D006593:Hexokinase