Genes encoding the phycobilisome rod substructure are clustered on the Anabaena chromosome: characterization of the phycoerythrocyanin operon.
Genes encoding the phycobilisome rod substructure are clustered on the Anabaena chromosome: characterization of the phycoerythrocyanin operon.
复制标题
编码藻胆体杆亚结构的基因聚集在鱼腥藻染色体上：藻红青蛋白操纵子的表征。
DOI：
10.1128/jb.174.8.2640-2647.1992
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发表时间：
1992
影响因子：
3.2
通讯作者：
Glazer,AN
中科院分区：
文献类型：
--
作者：
Swanson,RV;deLorimier,R;Glazer,AN
藻红蓝蛋白（phycoerythrocyanin，pec）操纵子是从鱼腥藻（Anabaena sp.）菌株PCC 7120中克隆的，编码4个基因pecBACE，位于C-藻蓝蛋白（cpc）操纵子的上游。这个pec-cpc簇包括藻胆体杆的结构组分的所有基因。基于藻红蓝蛋白β亚基的氨基末端序列的寡核苷酸探针用于克隆8.0-kbp的EcoRI片段，其通过测序确定为与先前克隆的CPC操纵子部分重叠。随后亚克隆并测序了对应于CPC操纵子上游区域的5.0-kbp EcoRI-ClaI片段。鉴定了五个开放阅读框，其转录极性与cpc基因的转录极性平行。pecB和pecA分别编码藻红蓝蛋白的β和α亚基。pecC编码藻红蓝蛋白相关的接头多肽LR 34.5，PEC。这些基因的身份证实了从纯化的藻胆体组分确定的氨基末端序列的协议。在pecC下游发现的与cpcE同源的基因被命名为pecE。cpcE基因产物参与藻蓝胆素发色团与藻蓝蛋白α亚基的连接。通过北方（RNA）分析观察到三种转录物。这些转录本中最丰富的1.35 kbp对应于β和α亚基基因，而丰度较低的转录本2.3和3.1 kbp分别对应于pecBAC和pecBACE。藻红蓝蛋白在弱光下培养的细胞中被强烈诱导。平行地，所有三种转录物在低光下培养的细胞中以高得多的水平存在。
The phycoerythrocyanin (pec) operon, cloned from Anabaena sp. strain PCC 7120, encodes four genes, pecBACE, located upstream of the C-phycocyanin (cpc) operon. This pec-cpc cluster includes all the genes for the structural components of the phycobilisome rod. Oligonucleotide probes based on the amino-terminal sequence of the phycoerythrocyanin beta subunit were used to clone an 8.0-kbp EcoRI fragment which was determined, by sequencing, to partially overlap the previously cloned cpc operon. A 5.0-kbp EcoRI-ClaI fragment corresponding to the region upstream of the cpc operon was subsequently subcloned and sequenced. Five open reading frames whose polarity of transcription is parallel to that of the cpc genes were identified. pecB and pecA encode the beta and alpha subunits of phycoerythrocyanin, respectively. pecC encodes the phycoerythrocyanin-associated linker polypeptide LR34.5,PEC. The identities of these genes are confirmed by agreement with amino-terminal sequences determined from purified phycobilisome components. A gene homologous to cpcE, found downstream of pecC, has been designated pecE. The cpcE gene product is involved in the attachment of the phycocyanobilin chromophore to the alpha subunit of phycocyanin. Three transcripts were observed by Northern (RNA) analyses. The most abundant of these transcripts, 1.35 kbp, corresponds to the beta and alpha subunit genes, whereas the less-abundant transcripts, 2.3 and 3.1 kbp, correspond to pecBAC and pecBACE, respectively. Phycoerythrocyanin is strongly induced in cells cultured under low light. In parallel, all three transcripts were present at much higher levels in cells cultured under low light.