IRE-BP regulates transcription of a receptor for this element; this element then detaches from that receptor at low pHs in the endosome.
IRE-BP regulates transcription of a receptor for this element; this element then detaches from that receptor at low pHs in the endosome. Siderophores bind this element. The proximal histidine coordinates an atom of this element. Oxygen binds an atom of this element in Complex IV of the ETC. This metal binds water in the active site of aconitase, an enzyme in which this element forms clusters with (*) sulfur. Cytochromes contain this metal in their active sites. Four porphyrin nitrogen atoms coordinate this element in a protein in which it can exist in either +2 or +3 oxidation states. For 10 points, name this metal which binds oxygen to transport it through the blood, since it's at the center of hemoglobin.
IRE-BP regulates transcription of a receptor for this element; this element then detaches from that receptor at low pHs in the endosome.
iron [or Fe]