Identification and characterization of a novel glucose-phosphorylating enzyme in Kluyveromyces lactis.
Recent data suggest that hexokinase KlHxk1 (Rag5) represents the only glucose-phosphorylating enzyme of Kluyveromyces lactis, which also is required for glucose signalling. Long-term growth studies of a K. lactis rag5 mutant, however, reveal slow growth on glucose, but no growth on fructose. Isolation of the permissive glucose-phosphorylating enzyme, mass spectrometric tryptic peptide analysis and determination of basic kinetic data identify a novel glucokinase (KlGlk1) encoded by ORF KLLA0C01,155g. In accordance with the growth characteristics of the rag5 mutant, KlGlk1 phosphorylates glucose, but fails to act on fructose as a sugar substrate. Multiple sequence alignment indicates the presence of at least one glucokinase gene in all sequenced yeast genomes.
Kettner
Karina
K
Technische Universität Dresden, Medizinische Fakultät Carl Gustav Carus, Institut für Physiologische Chemie, Dresden, Germany.
Müller
Eva-Christina
EC
Otto
Albrecht
A
Rödel
Gerhard
G
Breunig
Karin D
KD
Kriegel
Thomas M
TM
D000595:Amino Acid Sequence; D005632:Fructose / Q000378:metabolism; D005656:Fungal Proteins / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D015966:Gene Expression Regulation, Fungal; D005941:Glucokinase / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D005947:Glucose / Q000378:metabolism; D006801:Humans; D007716:Kluyveromyces / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development; D008969:Molecular Sequence Data; D010766:Phosphorylation; D010802:Phylogeny; D016415:Sequence Alignment; D013379:Substrate Specificity
D005656:Fungal Proteins; D005632:Fructose; D005941:Glucokinase; D005947:Glucose