Affinity chromatography-based identification of sRNA protein partners in Rhizobia

This project aims to identify novel protein partners of conserved trans-sRNAs in the α-proteobacterium Sinorhizobium meliloti. Trans-sRNAs (AbcR2, NfeR1 and EcpR1) were tagged at their 5’ ends with the MS2 aptamer. To identify the proteins associated with the trans-sRNAs we: i) expressed and purified the MS2 coat protein fused to maltose-binding protein (MS2-MBP); ii) purified MS2 tagged sRNAs conjugated with MS2-MBP via amylase column; and iii) subjected retained proteins to mass spectrometry analysis. To discard unspecific interactions we also analysed several control samples: i) samples expressing untagged trans-sRNAs; ii) samples expressing an MS2 tagged Rho-independent transcriptional terminator.