Cobbett Christopher S, Hussain Dawar, Haydon Michael J
Department of Genetics, University of Melbourne, Australia 3010.
New Phytol. 2003 Aug;159(2):315-321. doi: 10.1046/j.1469-8137.2003.00785.x.
Arabidopsis is remarkable for having eight members of the type 1 heavy metal-transporting P-type ATPase subfamily. Sequence analyses indicate that four, two of which may be targeted to plastids, are related to known Cu(I) transporters and contain N-terminal metal-binding site (MBS) motifs similar to those identified in other organisms. The remaining four are more closely related to known divalent cation transporters of prokaryotes. Three of these form a closely related group and are believed to be Zn(II) transporters. These contain a predicted N-terminal MBS that is a variant of those found in Cu transporters in addition to extended C-terminal regions that contain likely metal-binding sequences. Our current limited knowledge of the physiological roles of these transporters is reviewed and their evolutionary relationships are explored, including an hypothesis that some, particularly the putative divalent cation transporters, are derived from horizontal gene transfer events.
拟南芥的显著特点是拥有8个1型重金属转运P型ATP酶亚家族成员。序列分析表明，其中4个与已知的铜离子（Cu(I)）转运蛋白相关，其中2个可能定位于质体，它们含有与其他生物体中鉴定出的类似的N端金属结合位点（MBS）基序。其余4个与已知的原核生物二价阳离子转运蛋白关系更为密切。其中3个形成一个密切相关的组，被认为是锌离子（Zn(II)）转运蛋白。这些蛋白除了含有可能的金属结合序列的延伸C端区域外，还含有一个预测的N端MBS，它是在铜转运蛋白中发现的MBS的变体。本文综述了我们目前对这些转运蛋白生理作用的有限认识，并探讨了它们的进化关系，包括一种假说，即其中一些转运蛋白，特别是假定的二价阳离子转运蛋白，源自水平基因转移事件。
