Spectral properties of phytochrome Agp2 from Agrobacterium tumefaciens are specifically modified by a compound of the cell extract
Spectral properties of phytochrome Agp2 from Agrobacterium tumefaciens are specifically modified by a compound of the cell extract
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DOI：
10.1016/j.jphotobiol.2008.07.001
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发表时间：
2008-10-16
影响因子：
5.4
通讯作者：
Lamparter, Tilman
中科院分区：
文献类型：
--
作者：
Krieger, Alexander;Molina, Isabel;Lamparter, Tilman
光敏色素是广泛分布的光感受器，它们可以通过红色吸收Pr和远红色吸收Pfr形式之间的光进行转换。土壤细菌根癌农杆菌含有两种光敏色素，Agp 1和Agp 2，它们作为光调节组氨酸激酶。虽然大多数光敏色素在Pr形式中是稳定的，但Agp 2和少数其他光敏色素在黑暗中转化为Pfr。我们在先前的出版物中已经表明，重组Agp 2的光谱特性被来自农杆菌agp 1（-）/agp 2（-）双敲除突变体的细胞提取物的化合物修饰。在本工作中，我们进行了浓度系列研究，结果表明相互作用是特异性的，并且修饰因子的浓度约为。0.2穆M.我们还进行了一系列的混合实验与截短的蛋白质Agp 2-M2，其中包括N-末端发色团模块（501个氨基酸）。细胞提取物以非特异性方式抑制Agp 2-M2的光转化。在浓度系列中，当使用较低浓度的Agp 2-M2时，这种负面影响不太明显。在存在过量Agp 2-M2脱辅基蛋白的情况下，细胞提取物不再改变Agp 2的光谱特性。数据表明，细胞提取物的因子与Agp 2的N-末端部分特异性相互作用。(C)2008 Elsevier B. V.保留所有权利。
Phytochromes are widely distributed photoreceptors that are converted by light between the red absorbing Pr and the far-red absorbing Pfr form. The soil bacterium Agrobacterium tumefaciens contains two phytochromes, Agp1 and Agp2, which act as light-regulated histidine kinases. Whereas most phytochromes are stable in the Pr form, Agp2 and few other phytochromes convert into Pfr in darkness. We have shown in a previous publication that the spectral properties of recombinant Agp2 are modified by compounds of the cell extract from an Agrobacterium agp1(-)/agp2(-) double knockout mutant. In the present work we performed concentration series which show that the interaction is specific and that the modifying factor has a concentration of ca. 0.2 mu M. We have also performed a series of mixing experiments with the truncated protein Agp2-M2, which consists of the N-terminal chromophore module (501 amino acids). The cell extract inhibited the photoconversion of Agp2-M2 in an unspecific way. In concentration series, this negative effect was less pronounced when lower concentrations of Agp2-M2 were used. In the presence of excess Agp2-M2 apoprotein, the cell extract did no longer modify the spectral properties of Agp2. The data suggest that the factor of the cell extract interacts specifically with the N-terminal moiety of Agp2. (C) 2008 Elsevier B.V. All rights reserved.