UncI protein can mediate ring-assembly of c-subunits of FoF1-ATP synthase in vitro.
In F(o)F(1)-ATP synthase, multimeric c-subunits are assembled to a ring (c-ring) in the membranes that rotates as protons flow across F(o). We recently reported that assembly of c-ring of Propionigenium modestum in the membranes of Escherichia coli cells required P. modestum UncI, a product of the conserved uncI gene in the F(o)F(1) operon. However, cooperation with endogenous factors in E. coli remained unclear. Here, P. modestum c-subunit was synthesized in vitro in the presence of liposomes. When c-subunit alone was synthesized, it did not form c-ring. However, when c-subunit and P. modestum UncI were synthesized together, c-ring was formed. Fusion of the two kinds of liposomes, one containing only unassembled c-subunit and the other only UncI, resulted in gradual formation of c-ring. Thus, UncI alone can mediate in vitro post-translational c-ring assembly.
Ozaki
Yoko
Y
Chemical Resources Laboratory, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8503, Japan.
Suzuki
Toshiharu
T
Kuruma
Yutetsu
Y
Ueda
Takuya
T
Yoshida
Masasuke
M
D001426:Bacterial Proteins / Q000096:biosynthesis / Q000737:chemistry*; D025243:Bacterial Proton-Translocating ATPases / Q000096:biosynthesis / Q000737:chemistry*; D002474:Cell-Free System; D004591:Electrophoresis, Polyacrylamide Gel; D008081:Liposomes / Q000737:chemistry; D008565:Membrane Proteins / Q000737:chemistry; D045184:Propionigenium / Q000201:enzymology*; D021122:Protein Subunits / Q000096:biosynthesis / Q000737:chemistry
D001426:Bacterial Proteins; D008081:Liposomes; D008565:Membrane Proteins; D021122:Protein Subunits; D025243:Bacterial Proton-Translocating ATPases