Calcium-responsive expression of plasmid-mediated outer membrane proteins from Yersinia enterocolitica grown on solid media.
In vitro synthesis of proteins directed by Yersinia enterocolitica virulence plasmid DNA was studied using a cell-free Escherichia coli coupled transcription-translation system. Out of a total of twenty-four polypeptides synthesized in vitro, ten were identified (based on virtually identical molecular masses) as outer membrane proteins synthesized in vivo when virulent plasmid-bearing Y. enterocolitica cells were grown on four different solid media. Two high molecular weight outer membrane proteins synthesized in vivo by plasmid-bearing cells were not detected in the in vitro protein synthesizing system. Different plasmid-mediated outer membrane proteins were expressed in vivo in Y. enterocolitica grown on different media. Y. enterocolitica grown on media with high calcium concentration (1.4-1.5 mM) expressed twice the number of lower molecular weight outer membrane proteins than the organism grown on low calcium (238-311 microM) media. This is the first report that a single serotype has been shown to synthesize all the reported virulence plasmid-encoded outer membrane proteins including three new polypeptides. The constituents in the medium as well as the level of calcium appeared to have a regulatory role in plasmid gene expression for lower molecular weight outer membrane proteins.
Bhaduri
S
S
Agricultural Research Service, U.S. Department of Agriculture, Eastern Regional Research Center, Philadelphia, PA 19118.
D001425:Bacterial Outer Membrane Proteins / Q000096:biosynthesis* / Q000235:genetics / Q000302:isolation & purification; D002118:Calcium / Q000378:metabolism*; D003470:Culture Media; D004269:DNA, Bacterial / Q000302:isolation & purification; D004591:Electrophoresis, Polyacrylamide Gel; D004926:Escherichia coli / Q000378:metabolism; D005821:Genetic Techniques; D010957:Plasmids / Q000235:genetics; D015008:Yersinia enterocolitica / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*
D001425:Bacterial Outer Membrane Proteins; D003470:Culture Media; D004269:DNA, Bacterial; D002118:Calcium