Description:
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Heme, the iron-containing cofactor essential for the activity of many enzymes, is incorporated into its target proteins by unknown mechanisms. Here, an
<jats:italic>Escherichia coli</jats:italic>
hemoprotein, CcmE, was shown to bind heme in the bacterial periplasm by way of a single covalent bond to a histidine. The heme was then released and delivered to apocytochrome c. Thus, CcmE can be viewed as a heme chaperone guiding heme to its appropriate biological partner and preventing illegitimate complex formation.
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