NRAMP DEFINES A FAMILY OF MEMBRANE-PROTEINS
NRAMP DEFINES A FAMILY OF MEMBRANE-PROTEINS
复制标题
DOI：
10.1073/pnas.92.22.10089
复制
发表时间：
1995-10-24
影响因子：
11.1
通讯作者：
GROS, P
中科院分区：
文献类型：
--
作者：
CELLIER, M;PRIVE, G;GROS, P
Nramp（natural resistance-associated macrophage protein）是一个新近发现的膜整合蛋白家族，其生物化学功能尚不清楚。我们报告的Nramp同源物的鉴定从果蝇，植物水稻，和酵母酿酒酵母。蛋白质序列的最佳比对需要插入非常少的缺口，并显示出显着的序列同一性为28%（酵母），40%（植物），和55%（苍蝇）与哺乳动物蛋白质（46%，58%，和73%的相似性），以及一个共同的预测跨膜拓扑结构。该家族由编码10个跨膜片段的高度保守的疏水核心定义。这个疏水核心的其他功能包括几个不变的带电残基，序列保守的螺旋周期性，这表明保守和非保守的几个跨膜螺旋面，一致的运输签名的胞质内面对的膜，和结构决定因素先前描述的离子通道。这些特征表明，Nramp多肽形成了一组转运蛋白或通道的一部分，这些转运蛋白或通道作用于尚未鉴定的底物。
Nramp (natural resistance-associated macrophage protein) is a newly identified family of integral membrane proteins whose biochemical function is unknown. We report on the identification of Nramp homologs from the fly Drosophila melanogaster, the plant Oryza sativa, and the yeast Saccharomyces cerevisiae. Optimal alignment of protein sequences required insertion of very few gaps and revealed remarkable sequence identity of 28% (yeast), 40% (plant), and 55% (fly) with the mammalian proteins (46%, 58%, and 73% similarity), as well as a common predicted transmembrane topology. This family is defined by a highly conserved hydrophobic core encoding 10 transmembrane segments. Other features of this hydrophobic core include several invariant charged residues, helical periodicity of sequence conservation suggesting conserved and nonconserved faces for several transmembrane helices, a consensus transport signature on the intracytoplasmic face of the membrane, and structural determinants previously described in ion channels. These characteristics suggest that the Nramp polypeptides form part of a group of transporters or channels that act on as yet unidentified substrates.