A collagen-like surface glycoprotein is a structural component of the Bacillus anthracis exosporium
A collagen-like surface glycoprotein is a structural component of the Bacillus anthracis exosporium
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DOI：
10.1046/j.1365-2958.2000.03000.x
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发表时间：
2002-07-01
影响因子：
3.6
通讯作者：
Mock, M
中科院分区：
文献类型：
--
作者：
Sylvestre, P;Couture-Tosi, E;Mock, M
炭疽杆菌是炭疽病的病原体，是一种革兰氏阳性孢子形成细菌。外孢壁是成熟孢子周围最外层的珠被。在这里，我们描述的纯化和表征的孢子表面的免疫显性蛋白。这种蛋白质是丰富的，糖基化和外孢壁的一部分。测定其氨基端序列并鉴定相应的基因。它编码一个382个氨基酸残基的蛋白质，其中心部分含有一个GXX基序区域，呈现出与哺乳动物胶原蛋白的相似性。因此，这种胶原蛋白样表面蛋白被命名为BclA（炭疽杆菌胶原蛋白样蛋白）。BclA不存在于营养细胞中，仅在孢子和产孢细胞中检测到。一个潜在的启动子，依赖于西格玛因子西格玛（K），这是所需的各种事件在孢子形成后期，发现上游的bclA基因。构建并分析了bclA缺失突变体。电子显微镜研究表明，BclA是一个结构组件的细丝覆盖外层的孢子。
Bacillus anthracis, the aetiological agent of anthrax, is a Gram-positive spore-forming bacterium. The exosporium is the outermost integument surrounding the mature spore. Here, we describe the purification and the characterization of an immunodominant protein of the spore surface. This protein was abundant, glycosylated and part of the exosporium. The amino-terminal sequence was determined and the corresponding gene was identified. It encodes a protein of 382 amino acid residues, the central part of which contains a region of GXX motifs presenting similarity to mammalian collagen proteins. Thus, this collagen-like surface protein was named BclA (for Bacillus collagen-like protein of anthracis). BclA was absent from vegetative cells; it was detected only in spores and sporulating cells. A potential promoter, dependent on the sigma factor sigma(K), which is required for a variety of events late in sporulation, was found upstream from the bclA gene. A bclA deletion mutant was constructed and analysed. Electron microscopy studies showed that BclA is a structural component of the filaments covering the outer layer of the exosporium.