Structural basis for multimeric heme complexation through a specific protein-heme interaction -: The case of the third neat domain of IsdH from Staphylococcus aureus
Structural basis for multimeric heme complexation through a specific protein-heme interaction -: The case of the third neat domain of IsdH from Staphylococcus aureus
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DOI：
10.1074/jbc.m803383200
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发表时间：
2008-10-17
影响因子：
4.8
通讯作者：
Tsumoto, Kouhei
中科院分区：
文献类型：
--
作者：
Watanabe, Masato;Tanaka, Yoshikazu;Tsumoto, Kouhei
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.
