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目的：对表达Ｐｃ９０的ｃＤＮＡ克隆进行鉴定和分析并在大肠杆菌中予以表达。方法：将２．５ｋｂｐ的克隆（Ｐｃ９０－１）分别双向经外源性核酸酶Ⅲ删除，以制备亚克隆，末端终止法测序，并在大肠杆菌中表达。结果：经ＤＮＡ序列分析，这个克隆全长２５８１ｂｐ，翻译大约６１ｋＤａ的蛋白（５３２个氨基酸），开放阅读框到１５９６ｂｐ，随后是２个连续的终止码。值得注意的是３－末端的非翻译区相对较长。Ｐｃ９０－１在第１００到３５５个氨基酸之间有一个明显的重复区。将Ｐｃ９０－１的各亚克隆在大肠杆菌中表达，仅得到一约３５ｋＤａ的融合蛋白。Ｐｃ９０－１的ＤＮＡ序列与其它已知序列无同源性。Ｐｃ９０－１的酸性等电点及潜在的磷酸根结合位点均与前人报道的Ｐｃ９０的特征相符。结论：Ｐｃ９０－１可能表达Ｐｃ９０蛋白。
OBJECTIVE: To identify and analyze cDNA clones expressing Pc90 and express in E. coli. Methods: A 2.5kbp clone (Pc90-1) was deleted by exogenous nucleic acid enzyme Ⅲ in both directions to prepare a subclone, sequenced by terminal termination and expressed in E. coli. Results: After DNA sequence analysis, this clone was 2581bp in length, translating about 61kDa protein (532 amino acids), open reading frame to 1596bp, followed by two consecutive stop codons. It is noteworthy that the 3’-terminal untranslated region is relatively long. Pc90-1 has a distinct repeat between the 100th and 355th amino acids. Each subclone of Pc90-1 was expressed in E. coli resulting in only a fusion protein of approximately 35 kDa. The DNA sequence of Pc90-1 is not homologous to other known sequences. Pc90-1 acidic isoelectric point and potential phosphate binding sites are consistent with the previously reported characteristics of Pc90. Conclusion: Pc90-1 may express Pc90 protein.