Saurin W, Köster W, Dassa E
Unité de Programmation Moléculaire et Toxicologie génétique, CNRS URA 1444, Institut Pasteur, Paris, France.
Mol Microbiol. 1994 Jun;12(6):993-1004. doi: 10.1111/j.1365-2958.1994.tb01087.x.
Bacterial binding protein-dependent transport systems belong to the superfamily of ABC transporters, which is widely distributed among living organisms. Their hydrophobic membrane proteins are the least characterized components. The primary structures of 61 integral membrane proteins from 35 uptake systems were compared in order to characterize a short conserved hydrophilic segment, with a consensus EAA---G---------I-LP, located approximately 100 residues from the C-terminus. Secondary structure predictions indicated that this conserved region might be formed by two amphipathic alpha-helices connected by a loop containing the invariant G residue. We classified the conserved motifs and found that membrane proteins from systems transporting structurally related substrates specifically display a greater number of identical residues in the conserved region. We determined a consensus for each class of membrane protein and showed that these can be considered as signatures.
细菌结合蛋白依赖性转运系统属于ABC转运蛋白超家族，广泛分布于生物体中。它们的疏水膜蛋白是特征最少的组分。比较了来自35个摄取系统的61种整合膜蛋白的一级结构，以表征一个短的保守亲水片段，其共有序列为EAA---G---------I-LP，位于距C末端约100个残基处。二级结构预测表明，这个保守区域可能由两个两亲性α-螺旋形成，中间由一个含有不变G残基的环连接。我们对保守基序进行了分类，发现转运结构相关底物的系统中的膜蛋白在保守区域中特异性地显示出更多相同的残基。我们确定了每类膜蛋白的共有序列，并表明这些可以被视为特征序列。
