Molecular Cloning and Bioinformatics Analysis of kdpE Gene from Vibrio alginolyticus

The two-component regulatory system plays an important role in the growth and virulence of bacteria. In this study, the phosphate transcriptional regulatory protein （KdpE） gene of Vibrio alginolyticus strain HY9901 was cloned. Sequence analysis revealed that the length ofkdpE gene is 732 bp and encodes a putative protein of 243 amino acids. The predicted molecular weight （MW） of KdpE was 27.66 kD with an estimated pI of 5.01. Using SignalP 4.0 and TM- HMM Server 2.0 software, it was predicted that the KdpE protein was located in cytoplasm. It did not contain a signal peptide or a transmembranous region. A phylogenetic tree was constructed by MEGA 5.0 software, indicating that the KdpE of V. alginolyticus bad high genetic relationship with Vibrio campbellii and Vibrio parahaemolyticus. Using SWISS-MODEL work-space, the three-dimensional structures of conserved domain REC in the KdpE was determined. These results can provide a basis for further studies on the two-component regulatory systems of V. alginolyticus.

pSETsac B质粒构建及其对达卡气单胞菌kdp E基因的有痕与无痕敲除效率评价

为构建一种新型基因敲除质粒,以pSET4s和pK18mobsac B质粒为基础,通过PCR和酶切连接的方法,构建了新质粒pSETsac B,然后以pK18mobsac B质粒为对照,评价新建质粒对达卡气单胞菌kdp E基因的有痕敲除(带有四环素筛选标记)和无痕敲除效率。结果表明,两种质粒在有痕敲除效率上无差别,但在无痕敲除上,pSETsac B的敲除效率显著高于对照质粒pK18mobsac B。由于p SETsac B为穿梭性温敏质粒,因此,该质粒可望在革兰氏阳性和阴性菌的遗传机制研究中皆可发挥作用,本研究同时也为检视kdp E基因在达卡气单胞菌中的功能提供了前期的突变体材料。