马唐炭疽菌Colletotrichum hanaui三类Gα亚基基因的克隆与序列分析

Cloning and sequence analysis of three Gα subunit genes from Colletotrichum hanaui

利用同源克隆的方法,首先克隆马唐炭疽菌Gα亚基基因的同源片段,再通过TAIL-PCR扩增基因片段的上下游邻接序列,经过序列拼接最终成功获得了3类Gα亚基基因cagA,cagB和cagC的全长序列。根据基因序列及CDS序列,运用相关生物学软件对基因序列及其推测蛋白进行了生物信息学分析。基因cagA全长1 380 bp,含5个内含子,编码355个氨基酸;cagB全长1 283 bp,含3个内含子,编码353个氨基酸;cagC全长1 382 bp,含4个内含子,编码354个氨基酸。蛋白同源分析表明,该菌的这3类基因推测蛋白与稻瘟病菌、小麦赤霉病菌中同类基因编码蛋白高度同源,同源率均在75%以上,最高可达99%。

The gene fragments of Gα subunits were isolated from Colletotrichum hanaui by using homologue cloning method.The 5′and 3′ flanking sequences of the fragments were cloned by TAIL-PCR method and sequenced.After sequence assembling,the complete senquences of cagA,cagB and cagC were obtained.The structures of the three genes were characterized by comparing genome and CDS sequences.The cagA has an open reading frame（ORF） of 1 380 bp interrupted by 5 introns and putatively encodes a 355aa protein.The cagB has an ORF of 1 283 bp interrupted by 3 introns and putatively encodes a 353aa protein.The cagC has an ORF of 1382 bp interrupted by 4 introns and putatively encodes a 354aa protein.The results of amino acid sequence alignments showed that the predicated proteins were homologous with Gα subunits of other ascomycetous phytopathogens such as Magnaporthe grisea,Gibberella zeae,with the amino acid identity between 75% and 99%,respectively.