蛋白质序列与EST序列的反翻译联配

随着大规模技术的进步，收录到数据库中的序列很快，其中大多是未知功能的ＥＳＴｓ（表达序列标签，Ｅｘｐｒｅｓｓｅｄ Ｓｅｑｕｅｎｃｅ Ｔａｇｓ），一般通过蛋白南－ＥＳＴ序列联配来实验ＥＳＴ的功能提示。由于ＥＳＴ含有５％左右的误差，特别严重的是其中的移框误差，用通常的方法将ＥＳＴ按６个框翻译为蛋白南序列再进行联配难以处理移框误差问题。通过考虑ＥＳＴ序列各种可能的误差，将氨基酸序列反翻译为核苷酸序列，在核

REVERSE-TRANSLATED ALIGNMENT OF EST SEQUENCE WITH PROTEIN SEQUENCE

The sequences in database increase quickly along with the development of the high-throughput sequencing techniques, while most of the sequences are ESTs (Expressed Sequencing Tags) with unknown function. The homology alignment was often employed to identify the biological function of EST sequences, comparing all the six reading frames of EST against the selected protein databases at protein level. However, EST sequences contain nearly 5% sequencing errors, in which the frameshift errors made it difficult to treat precisely with traditional alignment. Addressing most of the possible sequencing errors, our alignment model is reverse-translateing the protein sequence into putative nucleotide sequence, which allowed direct comparison at nucleotide level. Such alignment between protein and EST sequences could be more accurate. And the knotty frameshifts in EST sequences could be identified with high quality.