The advent of interactome capture has allowed the unbiased identification of RNA binding proteins (RBPs) dramatically expanding their number and yielding novel insights into RNA biology (see also our recent review).
For interactome capture, RBPs are photo-cross-linked to their RNA targets. Subsequently, oligo-dT resin is used to capture polyadenylated RNAs and to co-purify with them the covalently bound proteins. RNAs that lack a ploy(A)-tail can, however, not be captured by this approach, limiting its broad application. In particular, prokaryotic organisms that do not polyadenylate their mRNAs are not amenable to interactome capture.
Now three manuscripts have been uploaded to bioRxiv by the Lilley, Krijgsveld, and Beckmann labs (we contributed to one of them). In all cases extraction with organic solvents is employed to purify cross-linked RNPs (see figure) circumventing the requirement of a poly(A)-sequence for RNP capture. Moreover, this approach also captures RBPs that bind to RNA as short as 30 nt.
The manuscripts can be found here: