Involved in heme (porphyrin) scavenging. Binds Fe(2+) and Fe(3+) heme but the largest fraction is Fe(2+) heme. Functions as a high-affinity heme binding protein and probably has a role in relaying heme-iron from cell wall-anchored isd proteins receptors to the probable permease IsdF. Binds 1 heme b (iron(II)-protoporphyrin IX) group per subunit. Repressed by fur in the presence of iron. The measured mass is that of heme-free IsdE. The measured mass is that of IsdE with a single heme bound. Belongs to the bacterial solute-binding protein 8 family.