Purification and Oligomerization of YaxAB Nanopores.

Large nanopores are powerful tools for studying conformational dynamics of folded proteins on a single-molecule level. Additionally, they can be used as real-time metabolite sensors. YaxAB is a large funnel-shaped, hetero-oligomeric nanopore of variable size. It has a unique shape that enables the detection of a broad range of folded proteins and it can even provide insight into protein dimerization. Here, we present a straightforward protocol for the expression and purification of the monomeric components of YaxAB, as well as for their assembly into functional nanopores. Furthermore, we describe how specific oligomeric sizes of the nanopore can be enriched.