The proteins this domain is found in are typically involved in regulating polymer accumulation in bacteria, particularly poly-beta-hydroxybutyrate (PHB) [1]. The N-terminal region is likely to be the DNA-binding domain (Pfam:PF07879) while this domain probably binds PHB (personal obs:C Yeats).

1: A repressor protein, PhaR, regulates polyhydroxyalkanoate (PHA) synthesis via its direct interaction with PHA. Maehara A, Taguchi S, Nishiyama T, Yamane T, Doi Y; J Bacteriol 2002;184:3992-4002. PMID:12081972