克雷伯氏菌果胶酸裂解酶基因K-PGL的获取与序列分析

Acquisition and Analysis of Pectin Lyase Gene K-PGL in Klebsiella sp.

【目的】研究克雷伯氏菌果胶酸裂解酶基因K-PGL的序列特征及其编码产物的理化性质、结构特征及同源性等。【方法】根据同源序列相似性设计引物,利用PCR、染色体步移等技术获得了基因序列,并对基因信号肽,疏水性和结构域等进行了分析。【结果】获得克雷伯氏菌2395 bp序列,其中K-PGL基因开放阅读框1710 bp,编码569个氨基酸,分子质量63.37 kDa,等电点7.17。编码蛋白具有信号肽酶切割位点,效率为0.864,序列中不含有半胱氨酸Cys,平均疏水指数为-0.449,为稳定存在的亲水蛋白。基因编码的蛋白具有内切聚半乳糖醛酸裂解酶基因家族特有的保守结构域,进化上与产酸克雷伯氏菌亲缘关系最近。【结论】获得了K-PGL基因序列及其特征,为进一步研究果胶酸裂解酶的生物学功能和应用提供依据。

【Objective】The sequence characteristics,including the physical-chemical properties,structure and homology relationship,of pec-tin acid lyase K-PGL of Klebsiella sp.were analyzed.【Method】The primers were designed according to the homologous K-PGL gene se-quence,and the gene was obtained by PCR and Genome Walking technology.The signal peptide,hydrophobicity and structural domain of gene were analyzed.【Result】A total of 2395 bp sequences of Klebsiella sp.were obtained.The open reading frame of K-PGL gene was 1710 bp,encoding 569 amino acids.The molecular mass and the isoelectric point of K-PGL was 63.37 kDa and 7.17,respectively.A signal peptide cleavage site with an efficiency of 0.864 was found existing in the K-PGL.There was no Cysteine in the K-PGL,and the hydropho-bic index was-0.449,which indicated that K-PGL was a stable existing protein.The K-PGL had a conserved domain unique to the endo-galacturonic acid lyase family,and was most close with Klebsiella oxytoca.【Conclusion】The sequence and characteristics of K-PGL gene were obtained in article,which would promote the further study of the function and application of pectin lyase.