SLAC1是一個最近識別出的,、存在于植物葉子中的陰離子通道，在那里它控制膨壓(turgor pressure),，從而控制植物氣門響應包括二氧化碳,、臭氧和干旱在內(nèi)的環(huán)境因素而開啟。現(xiàn)在,，細菌身上相當于SLAC1的一種物質(zhì)（即來自“流感嗜血桿菌”的“亞碲酸鹽抗性蛋白TehA”）的X-射線晶體結(jié)構(gòu)已被確定,。由結(jié)構(gòu)啟發(fā)而獲得的突變發(fā)生機理被用來分析該通道的導電性質(zhì)。氣孔的靜電特性表明,，不同陰離子之間的選擇性在很大程度上是離子脫水的能量成本的一個函數(shù),。
這項工作以及對該細菌蛋白功能所做的進一步研究表明，SLAC1 和TehA代表著由環(huán)境刺激控制的一大類選擇性陰離子通道,。（生物谷Bioon.com）
生物谷推薦英文摘要：
Nature doi:10.1038/nature09487
Homologue structure of the SLAC1 anion channel for closing stomata in leaves
Yu-hang Chen,Lei Hu,Marco Punta,Renato Bruni,Brandan Hillerich,Brian Kloss,Burkhard Rost,James Love,Steven A. Siegelbaum& Wayne A. Hendrickson
The plant SLAC1 anion channel controls turgor pressure in the aperture-defining guard cells of plant stomata, thereby regulating the exchange of water vapour and photosynthetic gases in response to environmental signals such as drought or high levels of carbon dioxide. Here we determine the crystal structure of a bacterial homologue (Haemophilus influenzae) of SLAC1 at 1.20 ? resolution, and use structure-inspired mutagenesis to analyse the conductance properties of SLAC1 channels. SLAC1 is a symmetrical trimer composed from quasi-symmetrical subunits, each having ten transmembrane helices arranged from helical hairpin pairs to form a central five-helix transmembrane pore that is gated by an extremely conserved phenylalanine residue. Conformational features indicate a mechanism for control of gating by kinase activation, and electrostatic features of the pore coupled with electrophysiological characteristics indicate that selectivity among different anions is largely a function of the energetic cost of ion dehydration.
