Open AccessStructure of 2‐oxo‐3‐deoxygalactonate kinase from Klebsiella pneumoniae
Author(s) -
Michalska Karolina,
Cuff Marianne E.,
Tesar Christine,
Feldmann Brian,
Joachimiak Andrzej
Publication year - 2011
Publication title -
acta crystallographica section d
Language(s) - English
Resource type - Journals
ISSN - 1399-0047
DOI - 10.1107/s0907444911021834
Subject(s) - galactose , biochemistry , enzyme , kinase , galactokinase , transferase , chemistry , klebsiella pneumoniae , phosphorylation , phosphotransferases , biology , escherichia coli , gene
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.