 E Bacterial two-hybrid assay reveals an interaction between SiaC and SiaD. The recombinant strains harboring different vectors were separately streaked on nonselective and dual-selective media (3-amino-1, 2, 4- triazole + streptomycin). NA represents the empty vector pBT or pTRG. The strain expressing LGF2 and Gal11P was used as positive controls 