Original article
Leptospira interrogans requires a functional heme oxygenase to scavenge iron from hemoglobin

https://doi.org/10.1016/j.micinf.2008.04.010Get rights and content
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Abstract

The transposon TnSC189 was used to construct a mutant in the putative heme oxygenase gene hemO (LB186) of Leptospira interrogans. Unlike its parent strain, the mutant grew poorly in medium in which hemoglobin was the sole iron source. The putative heme oxygenase was over expressed in a His-tagged form, purified and was demonstrated to degrade heme in vitro. Unexpectedly, it was also found that the L. interrogans growth rate was significantly increased when medium was supplemented with hemoglobin, but only if ferrous iron sources were absent. This result was mirrored in the expression of some iron-related genes and suggests the presence of regulatory mechanisms detecting Fe2+ and hemoglobin. This is the first demonstration of a functional heme oxygenase from a spirochete.

Keywords

Leptospira interrogans
Heme oxygenase
Heme
Iron
Gene regulation

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