title: Structure of 2-oxo-3-deoxygalactonate kinase from Klebsiella pneumoniae.
abstract: In most organisms, efficient D-galactose utilization requires the highly conserved Leloir pathway that converts D-galactose to D-glucose 1-phosphate. However, in some bacterial and fungal species alternative routes of D-galactose assimilation have been identified. In the so-called De Ley-Doudoroff pathway, D-galactose is metabolized into pyruvate and D-glyceraldehyde 3-phosphate in five consecutive reactions carried out by specific enzymes. The penultimate step in this pathway involves the phosphorylation of 2-oxo-3-deoxygalactonate to 2-oxo-3-deoxygalactonate 6-phosphate catalyzed by 2-oxo-3-deoxygalactonate kinase, with ATP serving as a phosphoryl-group donor. Here, a crystal structure of 2-oxo-3-deoxygalactonate kinase from Klebsiella pneumoniae determined at 2.1 Å resolution is reported, the first structure of an enzyme from the De Ley-Doudoroff pathway. Structural comparison indicates that the enzyme belongs to the ASKHA (acetate and sugar kinases/hsc70/actin) family of phosphotransferases. The protein is composed of two α/β domains, each of which contains a core common to all family members. Additional elements introduced between conserved structural motifs define the unique features of 2-oxo-3-deoxygalactonate kinase and possibly determine the biological function of the protein.
authors.affiliation: Midwest Center for Structural Genomics, Biosciences Division, Argonne National Laboratory, USA.
authors.forename: Karolina
authors.initials: K
authors.lastname: Michalska
authors.forename: Marianne E
authors.initials: ME
authors.lastname: Cuff
authors.forename: Christine
authors.initials: C
authors.lastname: Tesar
authors.forename: Brian
authors.initials: B
authors.lastname: Feldmann
authors.forename: Andrzej
authors.initials: A
authors.lastname: Joachimiak
mesh_terms: D000595:Amino Acid Sequence; D018360:Crystallography, X-Ray; D007711:Klebsiella pneumoniae / Q000201:enzymology*; D008958:Models, Molecular; D008969:Molecular Sequence Data; D011485:Protein Binding; D017510:Protein Folding; D011494:Protein Kinases / Q000737:chemistry* / Q000378:metabolism; D020836:Protein Structure, Quaternary; D017434:Protein Structure, Tertiary; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D040681:Structural Homology, Protein
chemical_list: D011494:Protein Kinases