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Publication Abstract from PubMed

To elucidate the heme acquisition system in pathogenic bacteria, we investigated the heme-binding properties of the third NEAT domain of IsdH (IsdH-NEAT3), a receptor for heme located on the surfaces of pathogenic bacterial cells, by using x-ray crystallography, isothermal titration calorimetry, examination of absorbance spectra, mutation analysis, size-exclusion chromatography, and analytical ultracentrifugation. We found the following: 1) IsdH-NEAT3 can bind with multiple heme molecules by two modes; 2) heme was bound at the surface of IsdH-NEAT3; 3) candidate residues proposed from the crystal structure were not essential for binding with heme; and 4) IsdH-NEAT3 was associated into a multimeric heme complex by the addition of excess heme. From these observations, we propose a heme-binding mechanism for IsdH-NEAT3 that involves multimerization and discuss the biological importance of this mechanism.

Structural basis for multimeric heme complexation through a specific protein-heme interaction: the case of the third neat domain of IsdH from Staphylococcus aureus.,Watanabe M, Tanaka Y, Suenaga A, Kuroda M, Yao M, Watanabe N, Arisaka F, Ohta T, Tanaka I, Tsumoto K J Biol Chem. 2008 Oct 17;283(42):28649-59. Epub 2008 Jul 30. PMID:18667422^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.