Salmochelins, siderophores of Salmonella enterica and uropathogenic Escherichia coli strains, are recognized by the outer membrane receptor IroN
Salmochelins, siderophores of Salmonella enterica and uropathogenic Escherichia coli strains, are recognized by the outer membrane receptor IroN
复制标题
DOI：
10.1073/pnas.0737682100
复制
发表时间：
2003-04-01
影响因子：
11.1
通讯作者：
Winkelmann, G
中科院分区：
文献类型：
--
作者：
Hantke, K;Nicholson, G;Winkelmann, G
一类被称为沙门菌素（salmochelins）的儿茶酚盐铁载体家族成员通过反相高效液相色谱法从鼠伤寒沙门氏菌（Salmonella enterica serotype Typhimurium）中分离出来，并通过傅里叶变换离子回旋共振 - 串联质谱（Fourier transform ion cyclotron resonance - MS/MS）和气相色谱 - 质谱（GC - MS）进行结构表征。沙门菌素1的初步结构包含两个由一个葡萄糖残基桥接的2,3 - 二羟基苯甲酰丝氨酸部分，该葡萄糖残基与一个部分的丝氨酸羟基和第二个部分的羧酸盐结合。沙门菌素2另外还包含一个与第三个2,3 - 二羟基苯甲酰丝氨酸部分相连的第二个葡萄糖残基。沙门菌素不是由iroBC突变体产生的，这表明IroB蛋白可能负责由与已知糖基转移酶的序列相似性所预测的糖基转移。用放射性标记的Fe - 55 - 沙门菌素进行的摄取实验以及用沙门菌素进行的生长促进试验表明，由肠杆菌属（S. enterica）和尿路致病性大肠杆菌菌株的iroA位点编码的IroN外膜受体是铁 - 沙门菌素转运的主要受体。
Members of a family of catecholate siderophores, called salmochelins, were isolated by reversed-phase HPLC from Salmonella enterica serotype Typhimurium and structurally characterized by Fourier transform ion cyclotron resonance-MS/MS and GC-MS. The tentative structure of salmochelin 1 contained two 2,3-dihydroxybenzoyiserine moieties bridged by a glucose residue, bound to the serine hydroxyl group of one moiety and the carboxylate of the second moiety. Salmochelin 2 contained in addition a second glucose residue linked to a third 2,3-dihydroxybenzoylserine moiety. Salmochelins were not produced by an iroBC mutant, which indicated that the lroB protein might be responsible for the glucosyl transfer predicted by sequence similarities to known glycosyltransferases. Uptake experiments with radiolabeled Fe-55-salmochelin and growth promotion tests with salmochelins showed that the IroN outer membrane receptor, encoded in the iroA locus of S. enterica and uropathogenic Escherichia coli strains, was the main receptor for ferric salmochelin transport.