A conserved domain in arthropod cuticular proteins binds chitin
A conserved domain in arthropod cuticular proteins binds chitin
复制标题
DOI：
10.1016/s0965-1748(01)00056-x
复制
发表时间：
2001-10-01
影响因子：
3.8
通讯作者：
Willis, JH
中科院分区：
文献类型：
--
作者：
Rebers, JE;Willis, JH
许多昆虫表皮蛋白包括被称为R&R共有序列的35-36个氨基酸基序。这一区域的广泛保存导致了它的功能是结合几丁质的建议。具有挑衅性的是，它没有序列相似性，以众所周知的半胱氨酸几丁质结合结构域中发现的几丁质酶和一些围食膜蛋白。利用在大肠杆菌中表达的融合蛋白。大肠杆菌，我们表明，从硬壳聚糖的蛋白质的R&R共识的扩展形式是必要的和足够的几丁质结合。重组AGCP 2b是冈比亚按蚊的一种表皮蛋白，在E.大肠杆菌和纯化的蛋白质结合到几丁质珠。来自AGCP 2b的65个氨基酸的延伸，包括R&R共有序列，赋予几丁质与谷胱甘肽-S-转移酶（GST）的结合。定向诱变的一些保守的氨基酸在这个扩展的R&R共识从硬角质层消除几丁质结合。因此，节肢动物有两个不同的类几丁质结合蛋白，那些与几丁质结合结构域中发现的凝集素，几丁质酶和围食膜（cysCBD）和那些与表皮蛋白几丁质结合结构域（non-cysCBD）。(C)2001爱思唯尔科技有限公司版权所有。
Many insect cuticular proteins include a 35-36 amino acid motif known as the R&R consensus. The extensive conservation of this region led to the suggestion that it functions to bind chitin. Provocatively, it has no sequence similarity to the well-known cysteine-containing chitin-binding domain found in chitinases and some peritrophic membrane proteins. Using fusion proteins expressed in E. coli, we show that an extended form of the R&R consensus from proteins of hard cuticles is necessary and sufficient for chitin binding. Recombinant AGCP2b, a putative cuticular protein from the mosquito Anopheles gambiae, was expressed in E. coli and the purified protein shown to bind to chitin beads. A stretch of 65 amino acids from AGCP2b, including the R&R consensus, conferred chitin binding to glutathione-S-transferase (GST). Directed mutagenesis of some conserved amino acids within this extended R&R consensus from hard cuticle eliminated chitin binding. Thus arthropods have two distinct classes of chitin binding proteins, those with the chitin-binding domain found in lectins, chitinases and peritrophic membranes (cysCBD) and those with the cuticular protein chitin-binding domain (non-cysCBD). (C) 2001 Elsevier Science Ltd. All rights reserved.