Structure of the Rhodobacter sphaeroides light-harvesting 1 beta subunit in detergent micelles.
Structure of the Rhodobacter sphaeroides light-harvesting 1 beta subunit in detergent micelles.
复制标题
洗涤剂胶束中球形红杆菌光捕获 1β 亚基的结构。
DOI：
10.1021/bi011576j
复制
发表时间：
2002
期刊：
影响因子：
2.9
通讯作者：
Girvin,MarkE
中科院分区：
文献类型：
--
作者：
Sorgen,PaulL;Cahill,SeanM;Krueger-Koplin,RayD;Krueger-Koplin,SuzanneT;Schenck,CraigC;Girvin,MarkE
球形红细菌的捕光1天线（LH 1）复合体将激发能漏斗式地传递到光合反应中心。我们的最终目标是从LH 1的各个亚基的结构中构建LH 1的结构，就像天线可以从其成分在膜模拟洗涤剂胶束中自组装一样。β亚基在Zwittergent 3：12胶束中采用类天然构象，如通过其进行组装的第一步结合BChla的能力所证明的。多维核磁共振光谱显示β亚基折叠为螺旋（L12-S25）-铰链（G26-W28）-螺旋（L29-W 44）结构，其中10个最低能量结构的螺旋区域的骨架均方根值分别为0.26和0.24 Ω。Mn 2+弛豫数据和蛋白质-去污剂NOE图谱显示C-末端螺旋嵌入胶束中，N-末端螺旋沿着去污剂胶束表面，它们的长轴之间成60°角。残基L12− W 44的15 N弛豫数据是典型的有序蛋白质，相关时间为8.25 ± 2.1 ns。将N-末端螺旋沿着膜表面放置的铰链区的存在可能是导致在LH 1和LH 2 β亚基之间观察到的功能差异的结构特征。
The light harvesting 1 antenna (LH1) complex fromRhodobacter sphaeroidesfunnels excitation energy to the photosynthetic reaction center. Our ultimate goal is to build up the structure of LH1 from structures of its individual subunits, much as the antenna can self-assemble from its components in membrane-mimicking detergent micelles. The β subunit adopts a nativelike conformation in Zwittergent 3:12 micelles as demonstrated by its ability to take the first step of assembly, binding BChla. Multidimensional NMR spectroscopy shows that the β subunit folds as a helix(L12-S25)−hinge(G26-W28)−helix(L29-W44)structure with the helical regions for the 10 lowest-energy structures having backbone rmsds of 0.26 and 0.24 Å, respectively. Mn2+relaxation data and the protein−detergent NOE pattern show the C-terminal helix embedded in the micelle and the N-terminal helix lying along the detergent micelle surface with a 60° angle between their long axes.15N relaxation data for residues L12−W44 are typical of a well-ordered protein with a correlation time of 8.25 ± 2.1 ns. The presence of the hinge region placing the N-terminal helix along the membrane surface may be the structural feature responsible for the functional differences observed between the LH1 and LH2 β subunits.