Streptococcus pyogenes quinolinate-salvage pathway-structural and functional studies of quinolinate phosphoribosyl transferase and NH3 -dependent NAD+ synthetase

FEBS J. 2017 Aug;284(15):2425-2441. doi: 10.1111/febs.14136. Epub 2017 Jul 7.

Abstract

Streptococcus pyogenes, also known as Group A Strep (GAS), is an obligate human pathogen that is responsible for millions of infections and numerous deaths per year. Infection manifestations can range from simple, acute pharyngitis to more complex, necrotizing fasciitis. To date, most treatments for GAS infections involve the use of common antibiotics including tetracycline and clindamycin. Unfortunately, new strains have been identified that are resistant to these drugs, therefore, new targets must be identified to treat drug-resistant strains. This work is focused on the structural and functional characterization of three proteins: spNadC, spNadD, and spNadE. These enzymes are involved in the biosynthesis of nicotinamide adenine dinucleotide (NAD+ ). The structures of spNadC and spNadE were determined. SpNadC is suggested to play a role in GAS virulence, while spNadE, functions as an NAD synthetase and is considered to be a new drug target. Determination of the spNadE structure uncovered a putative, NH3 channel, which may provide insight into the mechanistic details of NH3 -dependent NAD+ synthetases in prokaryotes.

Enzymes: Quinolinate phosphoribosyltransferase: EC2.4.2.19 and NAD synthetase: EC6.3.1.5.

Database: Protein structures for spNadC, spNadCΔ69A , and spNadE are deposited into Protein Data Bank under the accession codes 5HUL, 5HUO & 5HUP, and 5HUH & 5HUJ, respectively.

Keywords: NAD+ biosynthesis; NH3-dependent NAD+ synthetase; quinolinate phosphoribosyltansferase; quinolinate- salvage pathway.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Adenosine Triphosphate / chemistry
  • Adenosine Triphosphate / metabolism
  • Amide Synthases / chemistry
  • Amide Synthases / genetics
  • Amide Synthases / metabolism*
  • Apoenzymes / chemistry
  • Apoenzymes / genetics
  • Apoenzymes / metabolism
  • Bacterial Proteins / chemistry
  • Bacterial Proteins / genetics
  • Bacterial Proteins / metabolism*
  • Binding Sites
  • Catalytic Domain
  • Cluster Analysis
  • Computational Biology
  • Crystallography, X-Ray
  • Dimerization
  • Gene Deletion
  • Models, Molecular*
  • Nicotinamide-Nucleotide Adenylyltransferase / chemistry
  • Nicotinamide-Nucleotide Adenylyltransferase / genetics
  • Nicotinamide-Nucleotide Adenylyltransferase / metabolism*
  • Pentosyltransferases / chemistry
  • Pentosyltransferases / genetics
  • Pentosyltransferases / metabolism*
  • Protein Conformation
  • Protein Interaction Domains and Motifs
  • Protein Multimerization
  • Protein Structure, Quaternary
  • Quinolinic Acid / metabolism*
  • Recombinant Proteins / chemistry
  • Recombinant Proteins / metabolism
  • Streptococcus pyogenes / metabolism*
  • Structural Homology, Protein

Substances

  • Apoenzymes
  • Bacterial Proteins
  • Recombinant Proteins
  • Adenosine Triphosphate
  • Pentosyltransferases
  • nicotinate-nucleotide diphosphorylase (carboxylating)
  • Nicotinamide-Nucleotide Adenylyltransferase
  • nicotinic acid mononucleotide adenylyltransferase
  • Amide Synthases
  • NAD+ synthase
  • Quinolinic Acid