Bhaya D, Grossman A R
Department of Plant Biology, Carnegiie Institution of Washington, Stanford, CA 94305.
Nucleic Acids Res. 1993 Sep 25;21(19):4458-66. doi: 10.1093/nar/21.19.4458.
We are studying the multigene family encoding the fucoxanthin-chlorophyll binding proteins (fcp genes) that constitute the major component of the photosystem II-associated light harvesting complex in diatoms and brown algae. The characteristics of clusters of fcp genes on the genome of the diatom Phaeodactylum tricornutum are described. Sequence analysis of two genomic clones, PT5 and PT4, has demonstrated the presence of four fcp genes (fcpA, fcpB, fcpC, fcpD) on the former and two fcp genes (fcpE, fcpF) on the latter. The proteins encoded by the six characterized fcp genes range in similarity from 86% to 99%. The genes within each cluster are separated by short intergenic sequences (between 0.5 to 1.1 kb). None of these genes contain introns and all appear to be transcribed with short 5' transcribed, untranslated leader sequences; the transcription initiation sites were mapped 26 to 48 bases upstream of the ATG translation start site. Small conserved motifs are found among all of the genes just upstream of both the translation and the transcription start sites. The codon bias is similar in all of the fcp genes, with a predominance of pyrimidines in the third positions of codons of the four codon families. The two fcp genes that are most similar are fcpC and fcpD, and might represent a recent gene duplication. Southern analyses using fcp cDNAs as hybridization probes suggest that there may be additional sequences on the P. tricornutum genome that resemble the characterized fcp sequences.
我们正在研究编码岩藻黄质 - 叶绿素结合蛋白的多基因家族（fcp基因），这些蛋白构成了硅藻和褐藻中与光系统II相关的捕光复合体的主要成分。本文描述了硅藻三角褐指藻基因组上fcp基因簇的特征。对两个基因组克隆PT5和PT4的序列分析表明，前者存在四个fcp基因（fcpA、fcpB、fcpC、fcpD），后者存在两个fcp基因（fcpE、fcpF）。六个已鉴定的fcp基因所编码的蛋白质相似度在86%至99%之间。每个基因簇内的基因由短的基因间隔序列（0.5至1.1 kb）隔开。这些基因均不包含内含子，且似乎都转录有短的5'转录非翻译前导序列；转录起始位点位于ATG翻译起始位点上游26至48个碱基处。在翻译起始位点和转录起始位点上游的所有基因中都发现了小的保守基序。所有fcp基因的密码子偏好相似，四个密码子家族的密码子第三位嘧啶占优势。最相似的两个fcp基因是fcpC和fcpD，可能代表最近的基因复制。使用fcp cDNA作为杂交探针的Southern分析表明，三角褐指藻基因组上可能存在其他与已鉴定的fcp序列相似的序列。
