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Structure of N5-carboxyaminoimidazole ribonucleotide synthase (PurK) from Bacillus anthracis

Micheal L Tuntland1, Michael E Johnson, L W-M Fung

  • 1Department of Chemistry, University of Illinois at Chicago, Chicago, IL 60607, USA.

Acta Crystallographica. Section D, Biological Crystallography
|September 21, 2011
PubMed

Insights

We determined the structure of Bacillus anthracis N5-carboxyaminoimidazole ribonucleotide synthase (PurK) with bound Mg2+. This enzyme is crucial for purine biosynthesis and a potential antimicrobial target.

Area of Science:

  • Biochemistry
  • Structural Biology
  • Microbiology

Background:

  • N5-carboxyaminoimidazole ribonucleotide synthase (PurK) is a prokaryotic enzyme essential for purine biosynthesis.
  • PurK is a validated antimicrobial drug target due to its essential role in pathogen survival.

Purpose of the Study:

  • To elucidate the structural basis of PurK function and Mg2+ binding.
  • To provide insights for the rational design of novel antimicrobial agents targeting PurK.

Main Methods:

  • X-ray crystallography was employed to determine the apo structure of Bacillus anthracis PurK (baPurK).
  • The structure was solved at a resolution of 1.96 Å, revealing key active site features.

Main Results:

  • The apo structure of baPurK with Mg2+ in the active site was determined at 1.96 Å resolution.
  • A flexible B-loop (residues 149/150-157) near the active site and Mg2+ binding without co-ligands were observed.

Conclusions:

  • The determined structure provides a detailed view of the baPurK active site and its interaction with Mg2+.
  • Understanding these structural features can aid in developing selective inhibitors for PurK as antimicrobial drugs.

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