...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Biochemistry >Identification of an SH3-binding motif in a new class of methionine aminopeptidases from Mycobacterium tuberculosis suggests a mode of interaction with the ribosome
【24h】

Identification of an SH3-binding motif in a new class of methionine aminopeptidases from Mycobacterium tuberculosis suggests a mode of interaction with the ribosome

机译：新型结核分枝杆菌蛋氨酸氨基肽酶中SH3结合基序的鉴定表明与核糖体的相互作用方式。

获取原文
获取原文并翻译 | 示例
   

获取外文期刊封面封底 >>

       
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

The crystal structure of the methionine aminopeptidase (MetAP) from Mycobacterium tuberculosis (MtMetAP1c) has been determined in the apo- and methionine-bound forms. This is the first structure of a type I MetAP with a significant extension at the amino terminus. The catalytic domain is similar to that of Escherichia coli MetAP (EcMetAP), and the additional 40-residue segment wraps around the surface with an extended but well-defined structure. There are several members of the actinomyces family of bacteria that contain MetAPs with such N-terminal extensions, and we classify these as MetAP type Ic (MetAP1c). Some members of this family of bacteria also contain a second MetAP (type la) similar in size to EcMetAP. The main difference between the apo- and the methionine-bound forms of MtMetAP1c is in the conformation of the metal-binding residues. The position of the methionine bound in the active site is very similar to that found in many of the known members of this family. Side chains of several residues in the S1 and S1' subsites shift as much as 1.5 &ANGS; compared to EcMetAP. Residues 14-17 have the sequence Pro-Thr-Arg-Pro and adopt the conformation of a polyproline II helix. Model-building suggests that this PxxP segment can bind to an SH3 protein motif. Other type Ib and type Ic MetAPs with N-terminal extensions contain similarly located PxxP motifs. Also, several ribosomal proteins are known to include SH3 domains, one of which is located close to the tunnel from which the nascent polypeptide chain exits the ribosome. Therefore, it is proposed that the binding of MetAPs to the ribosome is mediated by a complex between a PxxP motif on the protein and an SH3 domain on the ribosome. It is also possible that zinc-finger domains, which are located at the extreme N-terminus of type I MetAPs, may participate in interactions with the ribosome.
机译：来自结核分枝杆菌（MtMetAP1c）的蛋氨酸氨基肽酶（MetAP）的晶体结构已确定为载脂蛋白和蛋氨酸结合形式。这是I型MetAP的第一个结构，在氨基末端有明显的延伸。催化结构域与大肠埃希菌MetAP（EcMetAP）相似，另外40个残基片段围绕表面包裹，具有扩展但结构明确的结构。放线菌属的细菌中有几个成员包含具有此类N端延伸的MetAP，我们将它们归类为MetAP Ic型（MetAP1c）。该细菌家族的某些成员还含有第二个MetAP（Ia型），大小与EcMetAP相似。 MtMetAP1c的载脂蛋白和蛋氨酸结合形式之间的主要区别在于金属结合残基的构象。结合在活性位点的蛋氨酸的位置与该家族许多已知成员中的位置非常相似。 S1和S1'亚位点的几个残基的侧链移位了1.5＆ANGS;与EcMetAP相比。残基14-17具有序列Pro-Thr-Arg-Pro，并采用聚脯氨酸II螺旋的构象。建立模型表明该PxxP区段可以结合SH3蛋白基序。具有N端延伸的其他Ib型和Ic型MetAP包含位置相似的PxxP基序。而且，已知几种核糖体蛋白包括SH3结构域，其中之一位于靠近新生多肽链从其离开核糖体的通道的位置。因此，提出MetAP与核糖体的结合是由蛋白质上的PxxP基序和核糖体上的SH3结构域之间的复合物介导的。位于I型MetAP的N端最末端的锌指结构域也可能参与与核糖体的相互作用。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号