Paulsen I T, Saier M H
Department of Biology, University of California at San Diego, La Jolla, CA 92093-0116, USA.
J Membr Biol. 1997 Mar 15;156(2):99-103. doi: 10.1007/s002329900192.
We describe a novel diverse family of metal ion transporter (CDF) proteins (the cation diffusion facilitator (CDF) family) with members occurring in both prokaryotes and eukaryotes. Thirteen sequenced protein members of the CDF family have been identified, several of which have been shown to transport cobalt, cadmium and/or zinc. All members of the CDF family possess six putative transmembrane spanners with strongest conservation in the four N-terminal spanners, and on the basis of the analyses, we present a unified structural model. Members of the family are shown to exhibit an unusual degree of size variation, sequence divergence, and differences in cell localization and polarity. The phylogenetic tree for the CDF family reveals that prokaryotic and eukaryotic proteins cluster separately. It allows functional predictions for some uncharacterized members of this family. A signature sequence specific for the CDF family is derived.
我们描述了一个新型的、多样的金属离子转运蛋白家族（阳离子扩散 facilitator，CDF 家族），其成员存在于原核生物和真核生物中。已鉴定出 CDF 家族的 13 个已测序蛋白成员，其中几个已被证明能转运钴、镉和/或锌。CDF 家族的所有成员都具有六个推定的跨膜结构域，在四个 N 端结构域中保守性最强，基于这些分析，我们提出了一个统一的结构模型。该家族成员表现出不同寻常程度的大小变化、序列差异以及细胞定位和极性差异。CDF 家族的系统发育树表明，原核生物和真核生物的蛋白分别聚类。这使得对该家族一些未表征成员的功能预测成为可能。推导得到了 CDF 家族特有的特征序列。
