Crystal structures and kinetics of N-acetylneuraminate lyase from Fusobacterium nucleatum

Acta Crystallogr F Struct Biol Commun. 2018 Nov 1;74(Pt 11):725-732. doi: 10.1107/S2053230X18012992. Epub 2018 Oct 17.


N-Acetyl-D-neuraminic acid lyase (NanA) catalyzes the breakdown of sialic acid (Neu5Ac) to N-acetyl-D-mannosamine (ManNAc) and pyruvate. NanA plays a key role in Neu5Ac catabolism in many pathogenic and bacterial commensals where sialic acid is available as a carbon and nitrogen source. Several pathogens or commensals decorate their surfaces with sialic acids as a strategy to escape host innate immunity. Catabolism of sialic acid is key to a range of host-pathogen interactions. In this study, atomic resolution structures of NanA from Fusobacterium nucleatum (FnNanA) in ligand-free and ligand-bound forms are reported at 2.32 and 1.76 Å resolution, respectively. F. nucleatum is a Gram-negative pathogen that causes gingival and periodontal diseases in human hosts. Like other bacterial N-acetylneuraminate lyases, FnNanA also shares the triosephosphate isomerase (TIM)-barrel fold. As observed in other homologous enzymes, FnNanA forms a tetramer. In order to characterize the structure-function relationship, the steady-state kinetic parameters of the enzyme are also reported.

Keywords: Fusobacterium nucleatum; N-acetylneuraminate lyase; enzyme kinetics; sialic acid catabolism.

MeSH terms

  • Bacterial Proteins / chemistry
  • Bacterial Proteins / genetics
  • Bacterial Proteins / metabolism
  • Crystallography, X-Ray
  • Fusobacterium nucleatum / enzymology*
  • Fusobacterium nucleatum / genetics
  • Hydrogen Bonding
  • Models, Molecular
  • N-Acetylneuraminic Acid / metabolism
  • Oxo-Acid-Lyases / chemistry*
  • Oxo-Acid-Lyases / genetics
  • Oxo-Acid-Lyases / metabolism*
  • Protein Conformation
  • Protein Folding
  • Pyruvic Acid / chemistry
  • Pyruvic Acid / metabolism
  • Schiff Bases / metabolism
  • Sequence Alignment
  • Tyrosine / chemistry


  • Bacterial Proteins
  • Schiff Bases
  • Tyrosine
  • Pyruvic Acid
  • Oxo-Acid-Lyases
  • N-acetylneuraminate lyase
  • N-Acetylneuraminic Acid