A new type of hemophore-dependent heme acquisition system of Serratia marcescens reconstituted in Escherichia coli.
The utilization by Serratia marcescens of heme bound to hemoglobin requires HasA, an extracellular heme-binding protein. This unique heme acquisition system was studied in an Escherichia coli hemA mutant that was a heme auxotroph. We identified a 92-kDa iron-regulated S. marcescens outer membrane protein, HasR, which alone enabled the E. coli hemA mutant to grow on heme or hemoglobin as a porphyrin source. The concomitant secretion of HasA by the HasR-producing hemA mutant greatly facilitates the acquisition of heme from hemoglobin. This is the first report of a synergy between an outer membrane protein and an extracellular heme-binding protein, HasA, acting as a heme carrier, which we termed a hemophore.
Ghigo
J M
JM
Unité de Physiologie Cellulaire, Institut Pasteur (CNRS URA 1300), Paris, France.
Létoffé
S
S
Wandersman
C
C
D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D001483:Base Sequence; D002352:Carrier Proteins; D003001:Cloning, Molecular; D004926:Escherichia coli / Q000235:genetics* / Q000378:metabolism; D015964:Gene Expression Regulation, Bacterial; D007501:Iron / Q000378:metabolism; D008565:Membrane Proteins / Q000235:genetics* / Q000378:metabolism; D008969:Molecular Sequence Data; D009154:Mutation; D012706:Serratia marcescens / Q000235:genetics / Q000378:metabolism*
D001426:Bacterial Proteins; D002352:Carrier Proteins; C093956:HasA protein, Serratia marcescens; D008565:Membrane Proteins; D007501:Iron