This repeat is found in proteins which are expressed under conditions of stress in bacteria. The repeat contains a highly conserved, characteristic sequence motif,KGG, that is also recognised by plants and lower eukaryotes and repeated in their LEA (late embryogenesis abundant) family of proteins, thereby rendering those proteins bacteriostatic. An example of such an LEA family is LEA_5, Pfam:PF00477. Further downstream from this motif is a Walker A, nucleotide binding, motif GXXXXGK(S,T), that in YciG of E coli, eg Swiss:Q8X7B4, is QSGGNKSGKS [URL]. YciG is expressed as part of a three-gene operon, yciGFE, and this operon is induced by stress and is regulated by RpoS, which controls the general stress-response in E coli. YciG was shown to be important for stationary-phase resistance to thermal stress and in particular to acid stress.

1: Physiological effects of Crl in Salmonella are modulated by sigmaS level and promoter specificity. Robbe-Saule V, Lopes MD, Kolb A, Norel F; J Bacteriol. 2007;189:2976-2987. PMID:17293430