Phase variation of hemoglobin utilization in Neisseria gonorrhoeae.

ABSTRACT: Most Neisseria gonorrhoeae isolates are unable to use human hemoglobin as the sole source of iron for growth (Hgb-), but a minor population is able to do so (Hgb+). This minor population grows luxuriously on hemoglobin, expresses two outer membrane proteins of 42 kDa (HpuA) and 89 kDa (HpuB), and binds hemoglobin under iron-stressed conditions. In addition to the previously reported HpuB, we identified and characterized HpuA, which is encoded by the gene hpuA, located immediately upstream of hpuB. Expression of both proteins was found to be controlled at the translational level by frameshift mutations in a run of guanine residues within the hpuA sequence encoding the mature HpuA protein. The "on-phase" hemoglobin-utilizing variants contained 10 G's, while the "off-phase" variants contained

SUBMITTER: Chen CJ 

PROVIDER: S-EPMC108006 | biostudies-literature | 1998 Mar

REPOSITORIES: biostudies-literature