Isolation of a gene encoding nodulin-like intrinsic protein of Escherichia coli.

Abstract

Members of the membrane intrinsic protein (MIP) family are expressed in various organisms including plants, insects, and vertebrates. E. coli is known to have a MIP member gene, glycerol facilitator (G1pF). Here we report the isolation of E. coli gene encoding BniP, bacterial nodulin-like intrinsic protein. BniP encodes a 231 amino acid, 24 kDa protein with 42% amino acid identity to Nod26, 38% amino acid identity to AQP1, and 29% amino acid identity to G1pF. Analysis of deduced amino acid sequence predicted a hydrophobic protein with six membrane-spanning domains. Expression of BniP in Xenopus oocytes induced slight increase in osmotic water permeability, but not glycerol or ion permeability. Our results showed that BniP is a new member of the MIP channel-forming proteins of E. coli.