Resonance assignment and secondary structure of DbpA protein from the European species, Borrelia afzelii

Libor Hejduk,Petr Rathner,Norbert Müller,Martin Strnad,Jan Sterba,Ryan O M Rego,Adriana Rathner,Libor Grubhoffer

doi:10.1007/s12104-021-10039-2

Abstract

Decorin binding proteins (Dbps) mediate attachment of spirochetes in host organisms during the early stages of Lyme disease infection. Previously, different binding mechanisms of Dbps to glycosaminoglycans have been elucidated for the pathogenic species Borrelia burgdorferi sensu stricto and B. afzelii. We are investigating various European Borrelia spirochetes and their interactions at the atomic level using NMR. We report preparative scale recombinant expression of uniformly stable isotope enriched B. afzelii DbpA in Escherichia coli, its chromatographic purification, and solution NMR assignments of its backbone and sidechain 1H, 13C, and 15N atoms. This data was used to predict secondary structure propensity, which we compared to the North American B. burgdorferi sensu stricto and European B. garinii DbpA for which solution NMR structures had been determined previously. Backbone dynamics of DbpA from B. afzelii were elucidated from spin relaxation and heteronuclear NOE experiments. NMR-based secondary structure analysis together with the backbone dynamics characterization provided a first look into structural differences of B. afzelii DbpA compared to the North American species and will serve as the basis for further investigation of how these changes affect interactions with host components.

Highlights

Borrelia burgdorferi sensu lato (s.l.) complex of genospecies is the causative agent of Lyme disease, the most common tick-borne disease in Europe and North America
Decorin binding proteins (Dbps) are important adhesins exposed on the surface of bacteria from the B. burgdorferi s.l. complex
Results from the TALOS-N secondary structure propensity prediction tool reveal that the secondary structure profile of European B. afzelii DbpA is generally similar to the DbpA solution NMR structures of two Borrelia species – B. burgdorferi s.s. (North America) and B. garinii (Europe) DbpAs (Fig. 2b, d)

Summary

Introduction

Borrelia burgdorferi sensu lato (s.l.) complex of genospecies is the causative agent of Lyme disease, the most common tick-borne disease in Europe and North America. Keywords NMR resonance assignment · Decorin-binding proteins · Borrelia afzelii Based on the sequence identity, DbpA variants differ in their binding affinity to different GAGs attached to decorin (Lin et al, 2014).

Results

Conclusion