桑树DNA连接酶Ⅰ基因MuLigI的获取和序列分析

Acquisition and Sequence Analysis of Mu LigⅠ Gene from Mulberry(Morus alba L.)

为进一步研究DNA连接酶Ⅰ在类病毒复制中的作用,以感染桑花叶萎缩类病毒的桑树叶片为材料,通过在同源基因保守区设计简并引物进行PCR扩增和c DNA末端扩增,获取桑树DNA连接酶Ⅰ基因。结果获得桑树DNA连接酶Ⅰ基因Mu Lig I长2730 bp的m RNA序列,基因编码区长2367 bp,编码788个氨基酸,含典型的DBD结构域（173~351 aa）和CD催化结构域（405~771 aa）,N端含有核定位（NLS）和线粒体定位信号（MLS）。研究所得桑树DNA连接酶Ⅰ基因具有保守的结构域和活性位点,可能和番茄的DNA连接酶Ⅰ基因一样,参与了桑花叶萎缩类病毒的复制过程。

For further study on the role of DNA ligase Ⅰ in the replication of viroid, the DNA ligase Ⅰ genewas obtained from MMDVd-infected mulberry leaf. The gene was amplified by degenerate primer designed inthe conserved domain according to the homologous genes and RACE methods. The results showed that them RNA sequence of Mu Lig Ⅰ was 2730 bp in length. The open reading frame（ORF） was 2367 bp andencoding 788 amino acid residues. There were conserved DBD domain（173-351 aa）, catalytic domain（405-771 aa）, and mitochondrion and nuclear location signal（MLS and NLS） in Mu LigⅠ. The Mu Lig Ⅰ gene in thisstudy contained conserved structural domain and active site, and like the DNA ligase Ⅰ gene of tomato, mightbe involved in the replication of MMDVd.