Three putative photosensory light, oxygen or voltage (LOV) domains with distinct biochemical properties from the filamentous cyanobacterium Anabaena sp PCC 7120
Three putative photosensory light, oxygen or voltage (LOV) domains with distinct biochemical properties from the filamentous cyanobacterium Anabaena sp PCC 7120
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DOI：
10.1562/2006-05-02-ra-888
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发表时间：
2006-11-01
影响因子：
3.3
通讯作者：
Ikeuchi, Masahiko
中科院分区：
文献类型：
--
作者：
Narikawa, Rei;Zikihara, Kazunori;Ikeuchi, Masahiko
光、氧或电压（LOV）域在植物、藻类和细菌中发现的光感受器的光致蛋白家族中起蓝光传感器的作用。我们检测到推定的LOV域（Alr 3170-LOV，All 2875-LOV和Alr 1229-LOV）的丝状蓝藻，鱼腥藻属PCC 7120的基因组中。这些蓝藻LOV结构域与已知的LOV结构域紧密聚类。Alr 3170-LOV和All 2875-LOV携带光敏LOV特有的保守半胱氨酸残基，而Alr 1229-LOV不携带。我们在大肠杆菌中表达了这三个LOV结构域并进行了纯化。事实上，Alr 3170-LOV和All 2875-LOV在点状念珠藻（Nostoc punctiforme）（一种相关物种）中是保守的，它们结合黄素单核苷酸，并且在蓝光照射下显示出已知LOV结构域特有的光谱变化。Alr 3170-LOV是完全光还原的，并且暗回复是缓慢的，而All 2875-LOV是缓慢光还原的，并且暗回复是快速的。为了比较，AvAll 2875-LOV在密切相关的A. variabilis也作为All 2875-LOV的同源物进行了研究。最后，我们观察到Alr 1229-LOV在N.斑点状没有显示黄素结合。
Light, oxygen or voltage (LOV) domains function as blue-light sensors in the phototropin family of photoreceptors found in plants, algae and bacteria. We detected putative LOV domains (Alr3170-LOV, All2875-LOV and Alr1229-LOV) in the genome of a filamentous cyanobacterium, Anabaena sp. PCC 7120. These cyanobacterial LOV domains are closely clustered with the known LOV domains. Alr3170-LOV and All2875-LOV carry the conserved cysteine residue unique to the photoactive LOV, whereas Alr1229-LOV does not. We expressed these three LOV domains in Escherichia coli and purified them. In fact, Alr3170-LOV and All2875-LOV that are conserved in Nostoc punctiforme, a related species, bound flavin mononucleotide and showed spectral changes unique to known LOV domains on illumination with blue light. Alr3170-LOV was completely photoreduced and dark reversion was slow, whereas All2875-LOV was slowly photoreduced and dark reversion was rapid. For comparison, AvAll2875-LOV in a closely related A. variabilis was also studied as a homolog of All2875-LOV. Finally, we observed that Alr1229-LOV that is not conserved in N. punctiforme showed no flavin binding.