title: Bacteriophage membrane protein P9 as a fusion partner for the efficient expression of membrane proteins in Escherichia coli.
abstract: Despite their important roles and economic values, studies of membrane proteins have been hampered by the difficulties associated with obtaining sufficient amounts of protein. Here, we report a novel membrane protein expression system that uses the major envelope protein (P9) of phage φ6 as an N-terminal fusion partner. Phage membrane protein P9 facilitated the synthesis of target proteins and their integration into the Escherichia coli cell membrane. This system was used to produce various multi-pass transmembrane proteins, including G-protein-coupled receptors, transporters, and ion channels of human origin. Green fluorescent protein fusion was used to confirm the correct folding of the expressed proteins. Of the 14 membrane proteins tested, eight were highly expressed, three were moderately expressed, and three were barely expressed in E. coli. Seven of the eight highly expressed proteins could be purified after extraction with the mild detergent lauryldimethylamine-oxide. Although a few proteins have previously been developed as fusion partners to augment membrane protein production, we believe that the major envelope protein P9 described here is better suited to the efficient expression of eukaryotic transmembrane proteins in E. coli.
authors.affiliation: School of Systems Biomedical Science, Soongsil University, 19 Sadang-Ro, Dongjak-Gu, Seoul 156-743, Republic of Korea.
authors.forename: Yuna
authors.initials: Y
authors.lastname: Jung
authors.affiliation: School of Systems Biomedical Science, Soongsil University, 19 Sadang-Ro, Dongjak-Gu, Seoul 156-743, Republic of Korea.
authors.forename: Hyeim
authors.initials: H
authors.lastname: Jung
authors.affiliation: School of Systems Biomedical Science, Soongsil University, 19 Sadang-Ro, Dongjak-Gu, Seoul 156-743, Republic of Korea. Electronic address: dblim@ssu.ac.kr.
authors.forename: Dongbin
authors.initials: D
authors.lastname: Lim
mesh_terms: D000595:Amino Acid Sequence; D017126:Bacteriophage phi 6 / Q000737:chemistry / Q000235:genetics*; D001483:Base Sequence; D003001:Cloning, Molecular; D003902:Detergents / Q000737:chemistry; D004926:Escherichia coli / Q000235:genetics*; D006801:Humans; D007473:Ion Channels / Q000737:chemistry / Q000235:genetics* / Q000302:isolation & purification; D008969:Molecular Sequence Data; D010957:Plasmids / Q000737:chemistry / Q000235:genetics; D043562:Receptors, G-Protein-Coupled / Q000737:chemistry / Q000235:genetics* / Q000302:isolation & purification; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification; D015854:Up-Regulation; D014764:Viral Proteins / Q000737:chemistry / Q000235:genetics* / Q000302:isolation & purification
chemical_list: D003902:Detergents; D007473:Ion Channels; D043562:Receptors, G-Protein-Coupled; D011993:Recombinant Fusion Proteins; D014764:Viral Proteins
keywords: Fusion partner; G-protein-coupled receptor; Membrane integration; Membrane protein; Phage φ6; Therapeutic antibody