TonB-dependent heme/hemoglobin receptor family protein
This model represents the TonB-dependent outer membrane heme/hemoglobin receptor/transporter found in bacteria which live in contact with animals (which contain hemoglobin or other heme-bearing globins) or legumes (which contain leghemoglobin). Some species having hits to this model such as Nostoc, Caulobacter and Chlorobium do not have an obvious source of hemoglobin-like proteins in their biological niche and so the possibility exists that they act on some other substance. [Transport and binding proteins, Cations and iron carrying compounds, Transport and binding proteins, Porins]