Table 1. YfiR-insensitive YfiN alleles.
| Location in YfiN | Residue change | Notes |
| First TM helix | A33T | |
| V40A | ||
| PAS, dimerization interface | P51S | |
| R58C | ||
| S59P | Equivalent mutation activates AwsX [35]. | |
| Y62H | ||
| A66V | ||
| A67P | ||
| A67V | ||
| V68A | ||
| F70L | ||
| E87K | Mutation present in Clin110. | |
| Second TM helix | G162S | |
| A171V | ||
| G173S | ||
| G173D | Mutation present in SCV20265. | |
| HAMP | D204N | Mutation at the equivalent position activates Tsr [59]. |
| A226T | ||
| L228F | ||
| E232D | Mutation at the equivalent position activates NarX [58]. |
PAS refers to the periplasmic PAS domain; HAMP refers to the HAMP domain.