自從上個(gè)世紀(jì)90年代起人們就已經(jīng)知道,，霍亂弧菌（Vibrio cholerae）中的霍亂毒素基因見于結(jié)合的噬菌體CTX?中,，這個(gè)噬菌體位于霍亂弧菌與“toxin-linked cryptic (TLC)”相鄰的基因組中,，后者是一個(gè)功能未知的染色體DNA成分。
現(xiàn)在,，TLC被發(fā)現(xiàn)相應(yīng)于TLC的基因組,，它是一個(gè)“衛(wèi)星細(xì)絲噬菌體”，利用第三個(gè)細(xì)絲噬菌體(fs2?)的形態(tài)發(fā)生基因形成感染性顆粒,。通過(guò)重建導(dǎo)致噬菌體DNA被獲取的事件和將這些事件與流行性菌種的基因組相對(duì)比,，Hassan等人建立了一個(gè)模型，該模型反映惡性霍亂弧菌是怎樣演化為成功的人類病原體的,。（生物谷Bioon.com）
生物谷推薦英文摘要：
Nature doi:10.1038/nature09408
Structure of a cation-bound multidrug and toxic compound extrusion transporter
Xiao He1, Paul Szewczyk1, Andrey Karyakin1, Mariah Evin1, Wen-Xu Hong1, Qinghai Zhang1 & Geoffrey Chang1
Department of Molecular Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, CB105, La Jolla, California 92037, USA
Transporter proteins from the MATE (multidrug and toxic compound extrusion)1 family are vital in metabolite transport in plants2, 3, directly affecting crop yields worldwide4. MATE transporters also mediate multiple-drug resistance (MDR) in bacteria and mammals5, modulating the efficacy of many pharmaceutical drugs used in the treatment of a variety of diseases6, 7, 8, 9. MATE transporters couple substrate transport to electrochemical gradients and are the only remaining class of MDR transporters whose structure has not been determined10. Here we report the X-ray structure of the MATE transporter NorM from Vibrio cholerae determined to 3.65??, revealing an outward-facing conformation with two portals open to the outer leaflet of the membrane and a unique topology of the predicted 12 transmembrane helices distinct from any other known MDR transporter. We also report a cation-binding site in close proximity to residues previously deemed critical for transport11. This conformation probably represents a stage of the transport cycle with high affinity for monovalent cations and low affinity for substrates.
