Members of this family are predicted integral membrane proteins of about 350 amino acids long and containing about 6 trans-membrane regions. Characterised members include LptF and LptG, two homologous tandem-encoded permeases of an export ATP transporter for lipopolysaccharide (LPS) assembly in most Gram-negative bacteria [1].

1: Identification of two inner-membrane proteins required for the transport of lipopolysaccharide to the outer membrane of Escherichia coli. Ruiz N, Gronenberg LS, Kahne D, Silhavy TJ; Proc Natl Acad Sci U S A. 2008;105:5537-5542. PMID:18375759