DNA sequence and regulation of the gene (cbpA) encoding the 42-kilodalton cytoplasmic membrane carotenoprotein of the cyanobacterium Synechococcus sp. strain PCC 7942.
DNA sequence and regulation of the gene (cbpA) encoding the 42-kilodalton cytoplasmic membrane carotenoprotein of the cyanobacterium Synechococcus sp. strain PCC 7942.
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编码蓝藻聚球藻属 42 千道尔顿细胞质膜胡萝卜素蛋白的基因 (cbpA) 的 DNA 序列和调控。
DOI：
10.1128/jb.171.6.3486-3493.1989
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发表时间：
1989
影响因子：
3.2
通讯作者：
Sherman,LA
中科院分区：
文献类型：
--
作者：
Reddy,KJ;Masamoto,K;Sherman,DM;Sherman,LA
蓝细菌聚球藻属菌株PCC 7942（Anacystis nidulans R2）的类胡萝卜素结合蛋白的编码基因（cbpA）已被克隆和测序。针对该蛋白质的多克隆抗体用于鉴定来自聚球藻菌株PCC 7942的λ gt 11表达文库的免疫反应性克隆。最初的阳性克隆（λ gtAN 42）含有0.9-kb的染色体片段，其用于检测来自λ EMBL 3文库的更大的染色体片段。λ EMBL 3重组体，λ EM 109，含有聚球藻菌株PCC 7942染色体的18-kb部分。cbpA的开放阅读框编码450个氨基酸，产生49，113道尔顿的蛋白质。疏水性图表明蛋白质可能具有49个残基的信号序列，其被切割以产生43，709道尔顿的成熟蛋白质。该蛋白已被定位在细胞质膜的生化程序，以及通过电子显微镜免疫细胞化学。北方（RNA）印迹分析表明cbpA的转录受DNA拓扑结构、光强度和铁浓度的紧密调控。转录在高光强度下的生长被极大地诱导，并且在缺铁条件下的生长期间被抑制。DNA促旋酶抑制剂新生霉素特异性地抑制光诱导的转录。在北方印迹中，基因特异性探针与长度为2.0和6.2 kb的两种大小的RNA杂交。由于cbpA似乎是6.2 kb转录物的一个组成部分，因此它可能是更大操纵子的一部分。
The gene (cbpA) coding for a carotenoid-binding protein of the cyanobacterium Synechococcus sp. strain PCC 7942 (Anacystis nidulans R2) has been cloned and sequenced. A polyclonal antibody against the protein was used to identify immunoreactive clones from a lambda gt11 expression library of Synechococcus strain PCC 7942. The initial positive clone (lambda gtAN42) contained a 0.9-kilobase (kb) chromosomal fragment, which was used to detect a larger chromosomal fragment from a lambda EMBL3 library. The lambda EMBL3 recombinant, lambda EM109, contained an 18-kb portion of the Synechococcus strain PCC 7942 chromosome. The open reading frame of cbpA encoded 450 amino acids which give rise to a protein of 49,113 daltons. The hydrophobicity plot indicates that the protein may have a 49-residue signal sequence which is cleaved to yield a mature protein of 43,709 daltons. The protein has been localized in the cytoplasmic membrane by biochemical procedures as well as by electron microscopic immunocytochemistry. Northern (RNA) blot analysis indicates that transcription of cbpA is tightly regulated by DNA topology, light intensity, and iron concentration. Transcription is greatly induced by growth under high light intensities and repressed during growth under iron-deficient conditions. The DNA gyrase inhibitor novobiocin specifically inhibited the light-induced transcription. In Northern blots, the gene-specific probe hybridized to two size classes of RNA, with lengths of 2.0 and 6.2 kb. Since cbpA appears to be a component of the 6.2-kb transcript, it is likely part of a larger operon.