The Neisseria meningitidis haemoglobin receptor: its role in iron utilization and virulence

Igor Stojijkovic, Vivian Hwa, Luc de Saint Martin, Peadar O'Gaora, Xavier Nassif, Fred Heffron, Magdalene So

Research output: Contribution to journalArticle

159 Scopus citations

Abstract

The Neisseris meningitidis haemoglobin receptor gene, hmbR, was cloned by complementation in a porphyrin‐requiring Escherichia coli mutant. hmbR encodes an 89.5 kDa outer membrane protein which shares amino acid homology with the TonB‐dependent receptors of Gram‐negative bacteria. HmbR had the highest similarity to Neisseria transferrin and lactoferrin receptors. The utilization of haemoglobin as an iron source required internalization of the haemin moiety by the cell. The mechanism of haemin internalization via the haemoglobin receptor was TonB‐dependent in E. coli. A N. meningitidis hmbR mutant was unable to use haemoglobin but could still use haemin as a sole iron source. The existence of a second N. meningitidis receptor gene, specific for haemin, was shown by the isolation of cosmids which did not hybridize with the hmbR probe, but which were able to complement an E. coli hemA aroB mutant on haemin‐supplemented plates. The N. meningitidis hmbR mutant was attenuated in an infant rat model for meningococcal infection, indicating that haemoglobin utilization is important for N. meningitidis virulence.

Original languageEnglish (US)
Pages (from-to)531-541
Number of pages11
JournalMolecular Microbiology
Volume15
Issue number3
DOIs
StatePublished - Feb 1995

ASJC Scopus subject areas

  • Microbiology
  • Molecular Biology

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