Evidence for a Two-Metal-Ion Mechanism in the Cytidyltransferase KdsB, an Enzyme Involved in Lipopolysaccharide Biosynthesis
2011

Two-Metal-Ion Mechanism in KdsB Enzyme for Lipopolysaccharide Biosynthesis

publication Evidence: high

Author Information

Author(s): Schmidt Helgo, Mesters Jeroen R., Wu Jing, Woodard Ronald W., Hilgenfeld Rolf, Mamat Uwe

Primary Institution: Institute of Biochemistry, Center for Structural and Cell Biology in Medicine, University of Lübeck, Lübeck, Germany

Hypothesis

Does the KdsB enzyme utilize a two-metal-ion mechanism for Kdo activation in lipopolysaccharide biosynthesis?

Conclusion

The study provides evidence that two magnesium ions are present in the active site of the KdsB enzyme, supporting the two-metal-ion hypothesis.

Supporting Evidence

  • The study shows that KdsB forms dimers and is active at high temperatures.
  • AA-LCKS exhibited maximum activity at 90°C and a pH optimum of 9.0.
  • Two magnesium ions were found in the active site, which is crucial for the enzyme's function.

Takeaway

The KdsB enzyme, which helps bacteria survive, uses two magnesium ions to activate a sugar needed for its protective outer layer.

Methodology

The enzyme was kinetically characterized and its crystal structure was determined at a resolution of 2.10 Å.

Digital Object Identifier (DOI)

10.1371/journal.pone.0023231

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