TY - JOUR
T1 - Protein C (OprC) of the outer membrane of Pseudomonas aeruginosa is a copper-regulated channel protein
AU - Yoneyama, Hiroshi
AU - Nakae, Taiji
PY - 1996/8
Y1 - 1996/8
N2 - Protein C (OprC) of the outer membrane of Pseudomonas aeruginosa forms small channels, as assayed by the liposome swelling method. We report here that OprC functions as a channel-forming and copper-binding protein. OprC purified to homogeneity formed a channel in planar lipid bilayers with an ion conductance of about 200 pS in 1 M NaCl. Cloning and sequencing of the gene encoding OprC revealed that it specified a polypeptide comprising 723 and 668 amino acid residues for the precursor and mature polypeptides (M(r) 73,372), respectively. The amino acid sequence of OprC showed the highest degree of similarity with that of NosA of Pseudomonas stutzeri (65% sequence identity) which conveys Cu2+ to intracellular acceptor(s). OprC showed high copper-binding activity (K(d) = 2.6 μM) in aqueous solution containing surfactant. The expression of OprC appeared to be repressed by exogenous Cu2+ and derepressed by anaerobiosis in the presence of nitrate. These results suggest that OprC might be involved in copper utilization.
AB - Protein C (OprC) of the outer membrane of Pseudomonas aeruginosa forms small channels, as assayed by the liposome swelling method. We report here that OprC functions as a channel-forming and copper-binding protein. OprC purified to homogeneity formed a channel in planar lipid bilayers with an ion conductance of about 200 pS in 1 M NaCl. Cloning and sequencing of the gene encoding OprC revealed that it specified a polypeptide comprising 723 and 668 amino acid residues for the precursor and mature polypeptides (M(r) 73,372), respectively. The amino acid sequence of OprC showed the highest degree of similarity with that of NosA of Pseudomonas stutzeri (65% sequence identity) which conveys Cu2+ to intracellular acceptor(s). OprC showed high copper-binding activity (K(d) = 2.6 μM) in aqueous solution containing surfactant. The expression of OprC appeared to be repressed by exogenous Cu2+ and derepressed by anaerobiosis in the presence of nitrate. These results suggest that OprC might be involved in copper utilization.
KW - Copper-binding protein
KW - Outer membrane
KW - Porin
KW - Protein C (OprC)
KW - Pseudomonas aeruginosa
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U2 - 10.1099/13500872-142-8-2137
DO - 10.1099/13500872-142-8-2137
M3 - Article
C2 - 8760927
AN - SCOPUS:0029820731
VL - 142
SP - 2137
EP - 2144
JO - Microbiology (Reading, England)
JF - Microbiology (Reading, England)
SN - 1350-0872
IS - 8
ER -