Structural model of the nucleotide-binding conserved component of periplasmic permeases.
Structural model of the nucleotide-binding conserved component of periplasmic permeases.
复制标题
周质通透酶的核苷酸结合保守成分的结构模型。
DOI：
10.1073/pnas.88.1.84
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发表时间：
1991
影响因子：
11.1
通讯作者：
Ames,GF
中科院分区：
文献类型：
--
作者：
Mimura,CS;Holbrook,SR;Ames,GF
17种细菌膜蛋白的氨基酸序列是质周透膜的组成部分，并在各种小分子和离子的摄取中起作用，它们彼此高度同源，并含有核苷酸结合蛋白特征的序列基序。已知这些蛋白质与ATP结合，并被假定为渗透膜的能量偶联成分。一些医学上重要的真核蛋白，包括多药耐药转运蛋白和囊性纤维化基因编码的蛋白，也与这个家族同源。通过对这17个蛋白的多序列比对，预测了一致序列、二级结构和表面暴露。通过已知三级结构的叠加，在腺苷酸激酶、p21ras和延伸因子Tu中发现了核苷酸结合蛋白中保守的二级结构基序。确定了预测保守构件的等效二级结构单元。这些与序列信息一起，作为与腺苷酸激酶比对的指导。通过类比腺苷酸激酶的结构，提出了渗透酶蛋白的atp结合结构域的结构模型。几种渗透酶突变的特征和生化数据支持该模型。
The amino acid sequences of 17 bacterial membrane proteins that are components of periplasmic permeases and function in the uptake of a variety of small molecules and ions are highly homologous to each other and contain sequence motifs characteristic of nucleotide-binding proteins. These proteins are known to bind ATP and are postulated to be the energy-coupling components of the permeases. Several medically important eukaryotic proteins, including the multidrug-resistance transporters and the protein encoded by the cystic fibrosis gene, are also homologous to this family. By multiple sequence alignment of these 17 proteins, the consensus sequence, secondary structure, and surface exposure were predicted. The secondary structural motifs that are conserved among nucleotide-binding proteins were identified in adenylate kinase, p21ras, and elongation factor Tu by superposition of their known tertiary structures. The equivalent secondary structural elements in the predicted conserved component were located. These, together with sequence information, served as guides for alignment with adenylate kinase. A model for the structure of the ATP-binding domain of the permease proteins is proposed by analogy to the adenylate kinase structure. The characteristics of several permease mutations and biochemical data lend support to the model.