Structural and catalytic properties and homology modelling of the human nucleoside diphosphate kinase C, product of the DRnm23 gene.
The human DRnm23 gene was identified by differential screening of a cDNA library obtained from chronic myeloid leukaemia-blast crisis primary cells. The over-expression of this gene inhibits differentiation and induces the apoptosis of myeloid precursor cell lines. We overproduced in bacteria a truncated form of the encoded protein lacking the first 17 N-terminal amino acids. This truncated protein was called nucleoside diphosphate (NDP) kinase CDelta. NDP kinase CDelta had similar kinetic properties to the major human NDP kinases A and B, but was significantly more stable to denaturation by urea and heat. Analysis of denaturation by urea, using size exclusion chromatography, indicated unfolding without the dissociation of subunits, whereas renaturation occurred via a folded monomer. The stability of the protein depended primarily on subunit interactions. Homology modelling of the structure of NDP kinase CDelta, based on the crystal structure of NDP kinase B, indicated that NDP kinase CDelta had several additional stabilizing interactions. The overall structure of the two enzymes appears to be identical because NDP kinase CDelta readily formed mixed hexamers with NDP kinase A. It is possible that mixed hexamers can be observed in vivo.
Institut de Biochimie et Génétique Cellulaires (UMR 5095), Centre National de la Recherche Scientifique et Université de Bordeaux-2, France.
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M
Erent
P
P
Gonin
J
J
Cherfils
P
P
Tissier
G
G
Raschellà
A
A
Giartosio
F
F
Agou
C
C
Sarger
M L
ML
Lacombe
M
M
Konrad
I
I
Lascu
D000595:Amino Acid Sequence; D015153:Blotting, Western; D002384:Catalysis; D004795:Enzyme Stability; D006358:Hot Temperature; D006801:Humans; D007527:Isoenzymes / Q000235:genetics* / Q000378:metabolism*; D008958:Models, Molecular; D008969:Molecular Sequence Data; D020559:Monomeric GTP-Binding Proteins / Q000235:genetics / Q000378:metabolism; D054778:NM23 Nucleoside Diphosphate Kinases; D009447:Neuroblastoma / Q000201:enzymology; D009701:Nucleoside-Diphosphate Kinase / Q000235:genetics* / Q000378:metabolism*; D011489:Protein Denaturation; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D013329:Structure-Activity Relationship; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D014407:Tumor Cells, Cultured; D014508:Urea / Q000494:pharmacology
D007527:Isoenzymes; D054778:NM23 Nucleoside Diphosphate Kinases; D014157:Transcription Factors; D014508:Urea; C517942:NME3 protein, human; D009701:Nucleoside-Diphosphate Kinase; D020559:Monomeric GTP-Binding Proteins