Purification, crystallization and preliminary crystallographic analysis of the SpaA backbone-pilin subunit from
Deepak Singh1, Ingemar von Ossowski, Airi Palva
1Regional Centre for Biotechnology, 180 Udyog Vihar Phase 1, Gurgaon, Haryana 122 016, India.
Abstract:
Lactobacillus rhamnosus GG, a widely used Gram-positive probiotic strain, is clinically well known for its perceived health-promoting effects. It has recently been shown to display proteinaceous pilus fibres (called SpaCBA) on its cell surface. Structurally, SpaCBA pili possess a characteristic three-pilin polymerized architecture, with repeating SpaA major pilins that form the backbone and two types of minor subunits (SpaB and SpaC). In this study, recombinant SpaA protein was purified, characterized and crystallized. The crystals diffracted to a resolution of 2.0 Å and belonged to space group C2, with unit-cell parameters a=227.9, b=63.2, c=104.3 Å, β=95.1°.
