Franzén L G, Frank G, Zuber H, Rochaix J D
Department of Molecular Biology, University of Geneva, Switzerland.
Mol Gen Genet. 1989 Oct;219(1-2):137-44. doi: 10.1007/BF00261169.
cDNA clones encoding three photosystem I subunits of Chlamydomonas reinhardtii with apparent molecular masses 13, 5 and 3 kDa (thylakoid polypeptides 28, 35 and 37; P28, P35 and P37, respectively) were isolated using gene specific oligonucleotides as probes. The sequences of these oligonucleotides were deduced from the N-terminal amino acid sequences of the proteins. The cDNAs were sequenced and used to probe Southern and Northern blots. The Southern blot analysis indicates that the proteins are encoded by single-copy genes. The mRNA sizes of the three components are 960 (P28), 1120 (P35) and 790 (P37) nucleotides. Comparison between the open reading frames of the cDNAs and the N-terminal amino acid sequences of the proteins indicates that the nascent polypeptides possess N-terminal transit sequences that are removed to give mature proteins of 11.0 (P28), 10.0 (P35) and 8.4 (P37) kDa. Analysis of the deduced protein sequences suggests that P28 and P35 are extrinsic membrane proteins and that P37 spans the thylakoid membrane. All three proteins have short transit peptides that probably route them to the stromal side of the thylakoid membrane.
利用基因特异性寡核苷酸作为探针，分离出了编码莱茵衣藻光系统I三个亚基的cDNA克隆，这三个亚基的表观分子量分别为13 kDa、5 kDa和3 kDa（类囊体多肽28、35和37；分别为P28、P35和P37）。这些寡核苷酸的序列是根据蛋白质的N端氨基酸序列推导出来的。对这些cDNA进行了测序，并用于探测Southern印迹和Northern印迹。Southern印迹分析表明，这些蛋白质由单拷贝基因编码。这三个组分的mRNA大小分别为960个核苷酸（P28）、1120个核苷酸（P35）和790个核苷酸（P37）。cDNA的开放阅读框与蛋白质的N端氨基酸序列之间的比较表明，新生多肽具有N端转运序列，这些序列在成熟后被去除，形成分子量分别为11.0 kDa（P28）、10.0 kDa（P35）和8.4 kDa（P37）的成熟蛋白质。对推导的蛋白质序列分析表明，P28和P35是外在膜蛋白，P37跨类囊体膜。所有这三种蛋白质都有短的转运肽，可能将它们引导至类囊体膜的基质侧。
