TY - JOUR
T1 - The Neisseria meningitidis haemoglobin receptor
T2 - its role in iron utilization and virulence
AU - Stojijkovic, Igor
AU - Hwa, Vivian
AU - de Saint Martin, Luc
AU - O'Gaora, Peadar
AU - Nassif, Xavier
AU - Heffron, Fred
AU - So, Magdalene
PY - 1995/2
Y1 - 1995/2
N2 - 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.
AB - 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.
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U2 - 10.1111/j.1365-2958.1995.tb02266.x
DO - 10.1111/j.1365-2958.1995.tb02266.x
M3 - Article
C2 - 7783623
AN - SCOPUS:0028968322
SN - 0950-382X
VL - 15
SP - 531
EP - 541
JO - Molecular Microbiology
JF - Molecular Microbiology
IS - 3
ER -