Elucidation of the translation initiation factor interaction network of Haloferax volcanii reveals coupling of transcription and translation in haloarchaea

Translation is an important step in gene expression. Initiation of translation is rate-limiting, and it is 13 phylogenetically more diverse than elongation or termination. Bacteria contain only three initiation 14 factors. In stark contrast, eukaryotes contain more than 10 (subunits of) initiation factors (eIFs). The 15 genomes of archaea contain many genes that are annotated to encode archaeal homologs of 16 eukaryotic initiation factors (aIFs). However, experimental characterization of aIFs is scarce and 17 mostly restricted to very few species. To broaden the view, the protein-protein interaction network of 18 aIFs in the halophilic archaeon Haloferax volcanii has been characterized. To this end, tagged 19 versions of 14 aIFs were overproduced, affinity isolated, and the co-isolated binding partners were 20 identified by peptide mass fingerprinting.