Enterobacter aerogenes OmpX, a cation-selective channel mar- and osmo-regulated.
The ompX gene of Enterobacter aerogenes was cloned. Its overexpression induced a decrease in the major porin Omp36 production and consequently a beta-lactam resistance was noted. Purified outer membrane protein X (OmpX) was reconstituted into artificial membranes and formed ion channels with a conductance of 20 pS in 1 M NaCl and a cationic selectivity. Both MarA expression and high osmolarity induced a noticeable increase of the OmpX synthesis in the E. aerogenes ATCC 13048 strain. In addition, OmpX synthesis increased under conditions in which the expression of the E. aerogenes major non-specific porins, Omp36 and Omp35, decreased.
Dupont
Myrielle
M
EA2197, IFR48, Faculté de Médecine, Université de la Méditerranée, 27 Bd Jean Moulin, 13385 Marseille Cedex 05, France.
Dé
Emmanuelle
E
Chollet
Renaud
R
Chevalier
Jacqueline
J
Pagès
Jean-Marie
JM
D000595:Amino Acid Sequence; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001483:Base Sequence; D002462:Cell Membrane / Q000648:ultrastructure; D003001:Cloning, Molecular; D017931:DNA Primers; D021902:Enterobacter aerogenes / Q000187:drug effects / Q000254:growth & development / Q000502:physiology*; D007473:Ion Channels / Q000502:physiology; D008826:Microbial Sensitivity Tests; D008969:Molecular Sequence Data; D018272:Porins / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D014882:Water-Electrolyte Balance
D000900:Anti-Bacterial Agents; D017931:DNA Primers; D007473:Ion Channels; D018272:Porins