SAF domains of the flagella basal body P-ring formation protein FlgA and the flp pilus assembly CpaB
FlgA is a putative periplasmic chaperone that assists in the formation of the flagellar P ring; CpaB is a protein invoved in the assembly of the flp pili, which are bacterial virulence factors mediating non-specific adherence to surfaces; these proteins appear to contain a single SAF domain. This intermediate family also contains the SAF domains of sialic acid synthetases and type III antifreeze proteins, which also share the same extensive core structure.
Jiyao W et al.(2023). "The conserved domain database in 2023.",