Szeto Tim H, Rowland Susan L, Habrukowich Cheryl L, King Glenn F
Department of Biochemistry, University of Connecticut Health Center, Farmington, Connecticut 06032, USA.
J Biol Chem. 2003 Oct 10;278(41):40050-6. doi: 10.1074/jbc.M306876200. Epub 2003 Jul 25.
MinD is a ubiquitous ATPase that plays a crucial role in selection of the division site in eubacteria, chloroplasts, and probably also Archaea. It was recently demonstrated that membrane localization of MinD is mediated by an 8-12-residue C-terminal motif termed the membrane targeting sequence or MTS. In this study we show that the MinD MTS is a transplantable lipid-binding motif that can effectively target heterologous proteins to the cell membrane. We demonstrate that eubacterial MTSs interact directly with lipid bilayers as an amphipathic helix, with a distinct preference for anionic phospholipids. Moreover, we provide evidence that the phospholipid preference of each MTS, as well as its affinity for biological membranes, has been evolutionarily "tuned" to its specific role in different bacteria. We propose a model to describe how the MTS is coupled to ATP binding to regulate the reversible membrane association of Escherichia coli MinD during its pole-to-pole oscillation cycle.
MinD是一种普遍存在的ATP酶,在真细菌、叶绿体以及可能在古细菌的分裂位点选择中发挥关键作用。最近有研究表明,MinD的膜定位是由一个8至12个残基的C末端基序介导的,该基序被称为膜靶向序列或MTS。在本研究中,我们表明MinD MTS是一种可移植的脂质结合基序,能够有效地将异源蛋白靶向到细胞膜。我们证明,真细菌的MTS作为两亲性螺旋直接与脂质双层相互作用,对阴离子磷脂有明显偏好。此外,我们提供的证据表明,每个MTS的磷脂偏好及其对生物膜的亲和力在进化过程中已被“调整”以适应其在不同细菌中的特定作用。我们提出了一个模型来描述MTS如何与ATP结合相偶联,以在大肠杆菌MinD的极到极振荡周期中调节其可逆的膜结合。