This family of proteins are functionally uncharacterised. However it is found in an O-antigen gene cluster in E. coli [1] and other bacteria [2] suggesting a role in O-antigen production. Feng et al. suggest that wbnG may code for a glycine transferase [2].

1: Sequence of the Escherichia coli O121 O-antigen gene cluster and detection of enterohemorrhagic E. coli O121 by PCR amplification of the wzx and wzy genes. Fratamico PM, Briggs CE, Needle D, Chen CY, DebRoy C; J Clin Microbiol. 2003;41:3379-3383. PMID:12843098

2: Structure of the Shigella dysenteriae 7 O antigen gene cluster and identification of its antigen specific genes. Feng L, Tao J, Guo H, Xu J, Li Y, Rezwan F, Reeves P, Wang L; Microb Pathog. 2004;36:109-115. PMID:14687563