Identification and purification of a hemoglobin-binding outer membrane protein from Neisseria gonorrhoeae.
The majority of in vitro-grown Neisseria gonorrhoeae strains were unable to use hemoglobin as the sole source of iron for growth (Hgb-), but a minor population was able to do so (Hgb+). The ability of Hgb+ gonococci to utilize hemoglobin as the iron source was associated with the expression of an iron-repressible 89-kDa hemoglobin-binding protein in the outer membrane. The N-terminal amino acid sequence of this protein revealed amino acids, from positions 2 to 16, identical to those of HpuB, an 85 kDa iron-regulated hemoglobin-haptoglobin utilization outer membrane protein of Neisseria meningitidis. Isogenic mutants constructed by allelic replacement with a meningococcal hpu::mini-Tn3erm construct no longer expressed the 89-kDa protein. Mutants could not utilize hemoglobin to support growth but still grew on heme. Thus, the gonococcal HpuB homolog is a functional hemoglobin receptor and is essential for growth with hemoglobin.
Chen
C J
CJ
Department of Medicine, School of Medicine, University of North Carolina, Chapel Hill 27599, USA.
Sparling
P F
PF
Lewis
L A
LA
Dyer
D W
DW
Elkins
C
C
D001425:Bacterial Outer Membrane Proteins / Q000302:isolation & purification* / Q000378:metabolism; D006454:Hemoglobins / Q000378:metabolism*; D009344:Neisseria gonorrhoeae / Q000378:metabolism*; D011485:Protein Binding
D001425:Bacterial Outer Membrane Proteins; D006454:Hemoglobins