Fig. 1.

Multiple sequence alignment of representative members of the gammaproteobacteria families Enterobacteriaceae and Vibrionaceae. Only nonredundant sequences (<   95% amino acid identity) are shown. The boundaries for the NTD and CTR are indicated. The depicted regular secondary-structure elements correspond to the crystal structure of E. coli Hfq (EcHfq) (PDB ID: 1HK9)¹⁴ with β-strands as arrows and the α-helix as a spiral. Positions are colored according to the Clustal color scheme: glycines are orange and prolines are yellow; other positions are colored according to conservation of chemical properties: hydrophobic in blue, aromatic in cyan, polar negative in purple, polar positive in red, and polar neutral in green. An alignment including other gammaproteobacteria families is shown in Fig. S2.