Catalytic and lectin domains in neuraminidase A from Streptococcus pneumoniae are capable of an intermolecular assembly: Implications for biofilm formation

Abstract

Neuraminidase A from Streptococcus pneumoniae (NanA) is a cell wall‐bound modular enzyme containing one lectin and one catalytic domain. Unlike homologous NanB and NanC expressed by the same bacterium, the two domains within one NanA molecule do not form a stable interaction and are spatially separated by a 16‐amino acid‐long flexible linker. In this work, the ability of NanA to form intermolecular assemblies was characterized using the methods of molecular modeling and bioinformatic analysis based on crystallographic data and by bringing together previously published experimental data. It was concluded that two catalytic domains, as well as one catalytic and one lectin domain, originating from two cell wall‐bound NanA molecules, can interact through a previously uncharacterized interdomain interface to form complexes stabilized by a network of intermolecular hydrogen bonds and salt bridges. Supercomputer modeling strongly indicated that artocarpin, an earlier experimentally discovered inhibitor of the pneumococcal biofilm formation, is able to bind to a site located in the catalytic domain of one NanA entity and prevent its interaction with the lectin or catalytic domain of another NanA entity, thus directly precluding the generation of intermolecular assemblies. The revealed structural adaptation is discussed as one plausible mechanism of noncatalytic participation of this potentially key pathogenicity enzyme in pneumococcal biofilm formation.

Selenium-based metabolic oligosaccharide engineering strategy for quantitative glycan detection

“…To begin with, HeLa cells were co-incubated with new-to-nature sialo-SeMOE probes. Treatment with Streptococcus pneumoniae neuraminidase A (sialidase) on the cell-surface milieu or in cell lysates, both demonstrated significant decreases in Se signal 32 (Fig. 2f ), indicating that most Se signal is localized in cell-surface sialylated glycans, and the signal is probe type-dependent.…”

“…LPS and IL-4 were purchased from Proteintech. Neuraminidase A (sialidase) from Streptococcus pneumoniae (NanA) was expressed and purified as previously described 32 . PNGase F was purchased from New England Biolabs (NEB).…”

“…Neuraminidase A (sialidase) from Streptococcus pneumoniae (NanA), was expressed and purified as previously described 32 . Expressed sialidase was concentrated to 7.0 mg/mL.…”

Bioinformatic analysis of subfamily-specific regions in 3D-structures of homologs to study functional diversity and conformational plasticity in protein superfamilies

“…The superimposed 3D-entries and corresponding sequence representation of alignment in FASTA format can be used as input to a local installation of Zebra3D to further improve bioinformatic analysis by fine-tuning the parameters. The Mustguseal protocol [39] , a step-by-step practical guide to its use and parameter selection [52] , as well as a discussion of various case-studies [14] , [41] , [53] , [54] , [55] are available in our recent publications. An illustrated user guide for the input preparation is available on-line at https://biokinet.belozersky.msu.ru/Zebra3D-input .…”

Role of Streptococcus pneumoniae extracellular glycosidases in immune evasion

“…A layer of adherent nanA deletion mutant bacteria was observed suggesting that NanA contributes to biofilm formation by promoting the aggregation of planktonic pneumococci (Parker et al, 2009). NanA molecules from two different cells interact using either the two catalytic domains or one catalytic and one lectin domain leading to the formation of complex structures stabilized by intermolecular bonding (Sharapova et al, 2021).…”