Chen C J, Sparling P F, Lewis L A, Dyer D W, Elkins C
Department of Medicine, School of Medicine, University of North Carolina, Chapel Hill 27599, USA.
Infect Immun. 1996 Dec;64(12):5008-14. doi: 10.1128/iai.64.12.5008-5014.1996.
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.
大多数体外培养的淋病奈瑟菌菌株无法将血红蛋白作为唯一的铁源用于生长（Hgb-），但有一小部分菌株能够利用血红蛋白生长（Hgb+）。Hgb+淋球菌利用血红蛋白作为铁源的能力与外膜中一种铁抑制性89 kDa血红蛋白结合蛋白的表达相关。该蛋白的N端氨基酸序列显示，第2至16位氨基酸与脑膜炎奈瑟菌的85 kDa铁调节血红蛋白-触珠蛋白利用外膜蛋白HpuB相同。用脑膜炎球菌hpu::mini-Tn3erm构建体通过等位基因替换构建的同基因突变体不再表达89 kDa蛋白。突变体无法利用血红蛋白支持生长，但仍能在血红素上生长。因此，淋球菌HpuB同源物是一种功能性血红蛋白受体，对于利用血红蛋白生长至关重要。
