Dertz Emily A, Xu Jide, Stintzi Alain, Raymond Kenneth N
Department of Chemistry, University of California, Berkeley, CA 94720-1460, USA.
J Am Chem Soc. 2006 Jan 11;128(1):22-3. doi: 10.1021/ja055898c.
The hexadentate triscatecholamide bacillibactin delivers iron to Bacillus subtilis and is structurally similar to enterobactin, although in a more oblate conformation. B. subtilis uses two partially overlapping permeases (1 and 2) to acquire iron from its endogenous siderophores (bacillibactin and itoic acid). Enterobactin and bacillibactin have opposite metal chiralities, different affinity for ferric ion, and dissimilar iron transport behaviors. The solution thermodynamic stability of ferric bacillibactin has been investigated through potentiometric and spectrophotometric titrations. The addition of a glycine to the catechol chelating arms causes a destabilization of the ferric complex of bacillibactin compared to ferric enterobactin. B. subtilis appears to express a separate receptor for enterobactin (permease 3), although enterobactin can also be transported through the permease for bacillibactin (permease 2).
六齿三儿茶酚酰胺杆菌铁载体将铁传递给枯草芽孢杆菌，其结构与肠杆菌素相似，不过构象更扁平。枯草芽孢杆菌利用两种部分重叠的通透酶（通透酶1和通透酶2）从其内源性铁载体（杆菌铁载体和伊托酸）获取铁。肠杆菌素和杆菌铁载体具有相反的金属手性、对铁离子的亲和力不同，且铁转运行为也不同。通过电位滴定和分光光度滴定研究了铁杆菌铁载体的溶液热力学稳定性。与铁肠杆菌素相比，在儿茶酚螯合臂上添加甘氨酸会导致杆菌铁载体的铁络合物不稳定。枯草芽孢杆菌似乎表达一种单独的肠杆菌素受体（通透酶3），不过肠杆菌素也可通过杆菌铁载体的通透酶（通透酶2）进行转运。
