NONRANDOM DISTRIBUTION OF AMINO-ACIDS IN THE TRANSMEMBRANE SEGMENTS OF HUMAN TYPE-I SINGLE SPAN MEMBRANE-PROTEINS
NONRANDOM DISTRIBUTION OF AMINO-ACIDS IN THE TRANSMEMBRANE SEGMENTS OF HUMAN TYPE-I SINGLE SPAN MEMBRANE-PROTEINS
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DOI：
10.1006/jmbi.1993.1066
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发表时间：
1993-02-05
影响因子：
5.6
通讯作者：
REITHMEIER, RAF
中科院分区：
文献类型：
--
作者：
LANDOLTMARTICORENA, C;WILLIAMS, KA;REITHMEIER, RAF
115个人类I型单跨质膜蛋白（胞外氨基端和胞内羧基端）的跨膜段和侧翼氨基酸分布具有非随机性。在这个样本中，Ile优先定位在疏水跨膜片段的氨基端区域，其次是Val，而Leu主要定位在片段的羧基端。虽然Gly残基优先位于跨膜段，但该残基被排除在羧基末端和邻近的边界区域之外。芳香残基（Try、色氨酸和苯丙氨酸）优先出现在细胞质边界，色氨酸也优先出现在胞外边界。胞外侧翼序列到跨膜段的氨基末端富含可引发螺旋形成的残基（Pro、Asn和Ser），而细胞质侧翼富含Arg和Lys，它们可能在那里起拓扑决定因素的作用。这些特殊氨基酸在跨膜段和侧翼区域的位置偏好表明，除了脂质-蛋白质相互作用外，这些残基还可能参与特定的蛋白质-蛋白质相互作用。提出了I型膜蛋白的一致序列基序，并讨论了其在这些片段的生物合成、折叠、组装和功能中的作用。
The distribution of amino acids in the transmembrane segments and flanking regions of 115 human type I single span (amino terminus extracellular and carboxyl terminus cytosolic) plasma membrane proteins was found to be non-random. In this sample, Ile was preferentially localized to the amino-terminal region of the hydrophobic transmembrane segments, followed by Val, while Leu predominated in the carboxyl-terminal half of the segment. Although Gly residues were preferentially located in the transmembrane segment, this residue was excluded from the carboxyl-terminal and adjacent boundary regions. Aromatic residues (Try, Trp and Phe) occurred preferentially at the cytoplasmic boundary, with Trp also favored at the extracellular boundary. The extracellular flanking sequence amino-terminal to the transmembrane segment was enriched in residues predicted to initiate helix formation (Pro, Asn and Ser), while Arg and Lys were enriched in the cytoplasmic flank where they may function as topological determinants. The positional preferences of these particular amino acids within the transmembrane segment and flanking regions suggests that, in addition to lipid-protein interactions, these residues may participate in specific protein-protein interactions. A consensus sequence motif for type I membrane protein is proposed and its role in the biosynthesis, folding, assembly and function of these segments is discussed.