The pyocin Sa receptor of Pseudomonas aeruginosa is associated with ferripyoverdin uptake.
We have used Tn5 mutagenesis to obtain a mutant resistant to pyocin Sa. When grown in iron-deficient succinate medium this mutant lacked an 85-kDa iron-regulated outer membrane protein (IROMP), and expression of a 75-kDa IROMP was increased compared with that in the parent strain. The mutant was deficient in pyoverdin biosynthesis and showed a 95% decrease in transport of ferripyoverdin purified from the parent strain, suggesting that the 85-kDa IROMP is the specific receptor for ferripyoverdin and pyocin Sa. The mutant compensated for the deficiency in pyoverdin biosynthesis and transport by exhibiting a fourfold increase in ferripyochelin transport. The low-level transport of ferripyoverdin in the Sa-resistant mutant, which extended to heterologous pyoverdins from other strains, suggests that Pseudomonas aeruginosa has a second ferripyoverdin uptake system of lower affinity and broader specificity.
Smith
A W
AW
Pharmaceutical Sciences Institute, Aston University, Birmingham, United Kingdom.
Hirst
P H
PH
Hughes
K
K
Gensberg
K
K
Govan
J R
JR
D001425:Bacterial Outer Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D001426:Bacterial Proteins; D004251:DNA Transposable Elements / Q000235:genetics; D007501:Iron / Q000378:metabolism*; D007502:Iron Chelating Agents / Q000378:metabolism; D033862:Iron-Binding Proteins; D016254:Mutagenesis, Insertional / Q000235:genetics; D009842:Oligopeptides; D033902:Periplasmic Binding Proteins; D010636:Phenols / Q000378:metabolism; D010860:Pigments, Biological / Q000096:biosynthesis / Q000378:metabolism*; D011550:Pseudomonas aeruginosa / Q000235:genetics / Q000378:metabolism*; D011709:Pyocins / Q000378:metabolism*
D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins; D004251:DNA Transposable Elements; D007502:Iron Chelating Agents; D033862:Iron-Binding Proteins; D009842:Oligopeptides; D033902:Periplasmic Binding Proteins; D010636:Phenols; D010860:Pigments, Biological; D011709:Pyocins; C025315:ferripyochelin; C042453:pyoverdin; D007501:Iron