氯粘康酸环异构酶基因克隆及序列研究

Cloning and sequence analysis of chloromuconate cycloisomerase gene

研究从土壤中分离出1株降解2,4-二氯酚能力较强的假单胞菌菌株“GT241-1”,并从中克隆出参与降解2,4-二氯酚的氯粘康酸环异构酶基因(dcpC),该基因编码的氯粘康酸环异构酶可将2,4-二氯-顺,顺-粘康酸转化为反式-2-氯-双烯内酯。采用的基因克隆策略是用Southern杂交对其邻近基因进行定位后构建基因组文库,再用斑点杂交从基因文库中筛选目的转化子。经序列测定得知dcpC基因编码区1110bp,且核苷酸和推测的编码氨基酸序列分析表明dcpC属氯粘康酸环异构酶基因家族,并与该基因家族的其他基因有一定差异。

A 2,4-dichlorophenol degrading Pseudomonas strain GT241-1 was isolated from a soil sample. The chloromuconate cycloisomerase gene, designated as dcpC which encodes chloromuconate cycloisomerase involved in transforming 2,4-dichloro-cis,cis-muconate into trans-2-chlorodienelactone,was cloned from this bacterium strain.The gene cloning strategy was to construct genomic library after location of its neighbouring gene by Southern blot and to screen the aim transformant by dot blotting.Sequencing results show that the length of dcpC is 1110bp.The sequence analysis of dcpC and the deduced amino acid show that dcpC belongs to chloromuconate cycloisomerase gene family and is different from other genes in the gene family.