From alpha to beta: identification of amino acids required for the N-acetyllactosamine-specific lectin-like activity of bundlin.
From alpha to beta: identification of amino acids required for the N-acetyllactosamine-specific lectin-like activity of bundlin.
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DOI：
10.1111/j.1365-2958.2009.06679.x
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发表时间：
2009-05
影响因子：
3.6
通讯作者：
Armstrong GD
中科院分区：
文献类型：
--
作者：
Humphries RM;Donnenberg MS;Strecker J;Kitova E;Klassen JS;Cui L;Griener TP;Mulvey GL;Armstrong GD
束形成菌毛(BFP)能促进典型肠源性大肠杆菌(EPEC)对人肠上皮细胞的黏附。BFP是Bundlin的聚合体，从不同来源分离的EPEC中已鉴定出9个Bundlin等位基因。根据其氨基酸序列，这些等位基因可分为两大类：α和β。β结合素也是N-乙酰乳糖胺(LacNAc)特异性凝集素，可与HEp-2细胞结合，而Alpha Bundlins则不显示这些特征。因此，α和βbundlin之间氨基酸序列异质性的四个表面暴露区域被研究为αbundlin中潜在的LacNAc特异性碳水化合物结合域。其中一个结构域的突变导致α不再与LacNAc或β-2细胞结合。相反，突变β3bundlin基因来编码该结构域的αbundlin序列会导致HEP-2细胞黏附的增加。该结构域在碳水化合物结合中的重要性得到了以下发现的支持：引入突变GENI➔GENNT后，α1结合碳水化合物的特异性从LacNAc改变为Lewis X糖链序列。
Bundle-forming pili (BFP) promote the adherence of typical enteropathogenic Escherichia coli (EPEC) to human intestinal epithelial cells. BFP are polymers of bundlin and nine bundlin alleles have been identified in EPEC isolated from diverse sources. These alleles are divided into two main groups, α and β, based on their amino acid sequences. Alpha bundlins are also N-acetyllactosamine- (LacNAc) specific lectins and bind to HEp-2 cells, whereas β bundlins do not display these characteristics. The four surface-exposed regions of amino acid sequence heterogeneity between α and β bundlin were therefore investigated as potential LacNAc-specific carbohydrate binding domains in α bundlin. Mutation of one of these domains, 137-GENNI-141, in α1 bundlin to that of β bundlin (136-SPDST-140) resulted in BFP that no longer bound to LacNAc or HEp-2 cells. Conversely, mutating the β3 bundlin gene to encode the α bundlin sequence at this domain resulted in the gain of HEp-2 cell adherence. The importance of this domain in carbohydrate binding is supported by the finding that introducing the mutation GENNI➔GENNT altered the α1 bundlin carbohydrate-binding specificity from LacNAc to the Lewis X glycan sequence.
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影响因子：
3.2
作者：
Anantha, TP;Stone, KD;Donnenberg, MS
通讯作者：
Donnenberg, MS
影响因子：
3.1
作者：
Anantha, RP;Stone, KD;Donnenberg, MS
通讯作者：
Donnenberg, MS
DOI：
10.1073/pnas.0707581104
发表时间：
2007-10-02
影响因子：
11.1
作者：
Helaine, Sophie;Dyer, David H.;Forest, Katrina T.
通讯作者：
Forest, Katrina T.
影响因子：
3.4
作者：
Hyland, Romney M.;Sun, Jiangxiao;Armstrong, Glen D.
通讯作者：
Armstrong, Glen D.
影响因子：
3
作者：
Hyland, Romney M.;Griener, Thomas P.;Armstrong, Glen D.
通讯作者：
Armstrong, Glen D.