Figure 2. Discovery of Hfq Binding RNAs.
A. Co-IP of Hfq bound RNAs using chromosomally FLAG tagged Hfq (adapted from Sittka et al.) [36]. Cellular extracts from hfqFLAG cells are prepared and co-IP with an α-FLAG antibody is performed. RNAs are extracted and modified to incorporate a polyA tail and 5'phosphate. A 5' adapter is ligated followed by cDNA synthesis and high-throughput sequencing to identify the bound RNAs. B. Genomic SELEX (adapted from Lorenz et al. and Zimmermann et al.) [68, 130]. A genomic library is created by random priming using primers that incorporate a T7 promoter and primer binding sites for reverse transcription and PCR. The library is transcribed to RNA and a binding reaction with Hfq is performed. Bound complexes are selected using filter binding. Bound RNAs are recovered from the filter followed by RT-PCR. The cycle is repeated multiple times followed by sequencing to identify the aptamers.