Domain found in uncharacterised family of membrane proteins. 1-3 copies found in each protein, with each copy flanked by transmembrane helices. Members of this family have a PH domain like structure [2].

1: New Knowledge from Old: In silico discovery of novel protein domains in Streptomyces coelicolor. Yeats C, Bentley S, Bateman A; BMC Microbiol 2003;3:3-3. PMID:12625841

2: Bacterial pleckstrin homology domains: a prokaryotic origin for the PH domain. Xu Q, Bateman A, Finn RD, Abdubek P, Astakhova T, Axelrod HL, Bakolitsa C, Carlton D, Chen C, Chiu HJ, Chiu M, Clayton T, Das D, Deller MC, Duan L, Ellrott K, Ernst D, Farr CL, Feuerhelm J, Grant JC, Grzechnik A, Han GW, Jaroszewski L, Jin KK, Klock HE, Knuth MW, Kozbial P, Krishna SS, Kumar A, Marciano D, McMullan D, Miller MD, Morse AT, Nigoghossian E, Nopakun A, Okach L, Puckett C, Reyes R, Rife CL, Sefcovic N, Tien HJ, Trame CB, van den Bedem H, Weekes D, Wooten T, Hodgson KO, Wooley J, Elsliger MA, Deacon AM, Godzik A, Lesley SA, Wilson IA. J Mol Biol. 2010 Feb 12;396(1):31-46. Epub 2009 Nov 10. PMID:19913036