This domain of unknown function is often found at the C-terminus of bacterial proteins, many of which are hypothetical, including proteins of the YicC family which have Pfam:PF03755 at the N-terminus. These include a protein important in the stationary phase of growth, and required for growth at high temperature [1]. Structural modelling suggests this domain may bind nucleic acids [2].

1: Three genes preceding pyrE on the Escherichia coli chromosome are essential for survival and normal cell morphology in stationary culture and at high temperature. Poulsen P, Jensen KF; Res Microbiol 1991;142:283-288. PMID:1925027

2: Ab Initio Modeling Led Annotation Suggests Nucleic Acid Binding Function for Many DUFs. Rigden DJ; OMICS 2011;0:0-0. PMID:21348639