CHARACTERIZATION OF THE LIGHT-REGULATED OPERON ENCODING THE PHYCOERYTHRIN-ASSOCIATED LINKER PROTEINS FROM THE CYANOBACTERIUM FREMYELLA-DIPLOSIPHON
CHARACTERIZATION OF THE LIGHT-REGULATED OPERON ENCODING THE PHYCOERYTHRIN-ASSOCIATED LINKER PROTEINS FROM THE CYANOBACTERIUM FREMYELLA-DIPLOSIPHON
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DOI：
10.1128/jb.172.7.4072-4081.1990
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发表时间：
1990-07-01
影响因子：
3.2
通讯作者：
GROSSMAN, AR
中科院分区：
文献类型：
--
作者：
FEDERSPIEL, NA;GROSSMAN, AR
光合作用生物体中的许多生物过程可以由光量或光质或两者共同调节。特定波长的光对光合作用装置组成的影响的一个独特的例子发生在蓝藻身上，它们经历了互补的显色适应。这些生物改变其捕光细胞器的组成，藻胆体，并表现出独特的形态特征作为入射光的波长的函数。Fremyella diplosiphon是一种丝状蓝藻，它通过激活cpeBA操纵子的转录来响应绿色光，cpeBA操纵子编码有色捕光成分藻红蛋白。我们已经分离并测定了另一个操纵子cpeCD的完整核苷酸序列，该操纵子编码与藻胆体中的藻红蛋白六聚体相关的连接蛋白。CpeCD操纵子在绿光下被激活，并表达为两个主要的转录本，具有相同的5‘’起点但不同的3‘’末端。对双虹吸藻培养物中转录物从红光向绿光转移的动力学分析表明，cpeBA和cpeCD操纵子是协同调控的。在两个操纵子转录起始点的上游都发现了一个共同的17碱基对序列。将预测的藻红蛋白相关连接蛋白CPEC和cpeD的氨基酸序列与其他已鉴定的杆状连接蛋白序列进行比较，发现有49个不变残基，其中大部分位于蛋白质的氨基末端。
Many biological processes in photosynthetic organisms can be regulated by light quantity or light quality or both. A unique example of the effect of specific wavelengths of light on the composition of the photosynthetic apparatus occurs in cyanobacteria that undergo complementary chromatic adaptation. These organisms alter the composition of their light-harvesting organelle, the phycobilisome, and exhibit distinct morphological features as a function of the wavelength of incident light. Fremyella diplosiphon, a filamentous cyanobacterium, responds to green light by activating transcription of the cpeBA operon, which encodes the pigmented light-harvesting component phycoerythrin. We have isolated and determined the complete nucleotide sequence of another operon, cpeCD, that encodes the linker proteins associated with phycoerythrin hexamers in the phycobilisome. the cpeCD operon is activated in green light and expressed as two major transcripts with the same 5'' start site but differing 3'' ends. Analysis of the kinetics of transcript accumulation in cultures of F. diplosiphon shifted from red light to green light and vice versa shows that the cpeBA and cpeCD operons are regulated coordinately. A common 17-base-pair sequence is found upstream of the transcription start sites of both operons. A comparison of the predicted amino acid sequences of the phycoerythrin-associated linker proteins CpeC and cpeD with sequences of other previously characterized rod linker proteins shows 49 invariant residues, most of which are in the amino-terminal half of the proteins.