The structure for one MBOAT protein, DltB from
Streptococcus thermophilus (), has been solved. DltB performs D-alanylation of cell-wall
teichoic acid. It contains a ring of 11 transmembrane helices surrounding a tunnel that goes through the biological membrane. The tunnel connects to a partner, DltC, which carries the D-alanine to the conserved histidine residue of DltB MBOAT located at the bottom of the funnel. A computational model of human
ghrelin O-acyltransferase (GOAT) (Q96T53) revealed a transmembrane channel that facilitates octanoylation of the peptide hormone
ghrelin. DltB and GOAT share structural similarities in their homologous regions, suggesting a common core fold for MBOAT family members. == Human proteins with this domain ==