Crystal structures and kinetics of N‐acetylneuraminate lyase from Fusobacterium nucleatum. Issue 11 (2nd November 2018)

• Record Type: Journal Article
• Authors: Kumar, Jay Prakash; Rao, Harshvardhan; Nayak, Vinod; Ramaswamy, S.
• Is Part Of: Acta crystallographica. Volume 74:Issue 11(2018:Nov.)
• Page Start: 725
• Page End: 732
• Publication Date: 2018-11-02
• Subjects: N‐acetylneuraminate lyase -- sialic acid catabolism -- enzyme kinetics -- Fusobacterium nucleatum; Crystallography -- Periodicals; Crystals -- Periodicals; 548
• DOI: 10.1107/S2053230X18012992
• Languages: English
• ISSNs: 2053-230X

Abstract

Abstract : Structures of N ‐acetyl‐d ‐neuraminic acid lyase in the ligand‐free form and of a covalent Schiff base adduct are reported. The structure and kinetic data reveal the conserved nature of these proteins among Gram‐negative bacteria. Abstract : 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.