幽门螺杆菌儿童分离株尿素酶基因B的克隆及序列分析

Cloning and sequence analysis of UreB of Helicobacter pylori isolated from children

目的克隆幽门螺杆菌(Hp)临床儿童分离株尿素酶B(UreB)基因入pGEX-4T-1表达载体,并进行测序及基因比对分析,为以UreB作为Hp疫苗分子的口服疫苗研制奠定基础。方法根据GenBank中HpUreB序列,设计一对特异性引物PCR扩增Hp临床儿童分离株UreB全长基因,EcoRI及NotI酶切后与做相应酶切的pGEX-4T-1连接,转化大肠杆菌BL21,提取质粒进行双酶切鉴定及基因测序,并对测序结果进行比对分析。结果以Hp儿童分离株GZCH1为模板,成功扩增了UreB基因,基因大小为1710bp,重组pGEX-4T-1-Ure双酶切鉴定可见目的片段,测序结果显示UreB在正确阅读框中,序列比对分析显示其与相关报道序列核苷酸和氨基酸一致性达98%。Hp儿童分离株GZCH1UreB序列已登录GenBank(登录号:FJ455126)。结论从Hp儿童分离株GZCH1中成功克隆了UreB基因,为UreBHp口服疫苗研制奠定了基础。

Objective To clone UreB gene of Helicobacter pylori （ H. pylori） isolated from children to pGEX-4T-1 expression plasmid, and do sequence analysis. Methods A pair of specific primer was designed according to H. pylori UreB gene in the GenBank. Using H. pylori strains isolated from children as a template, a UreB gene was obtained by PCR. After EcoR I and Not I digestion, the PCR production was linked with pGEX-4T-1 which was digested with the same enzymes. The recombinant plasmid was transformed into E. coli BI21 and identified by double enzyme digestion and sequence analysis. The sequence results were compared with the gene sequence in the GenBank. Results A UreB gene was successfully amplified from children＇s H. pylori strain GZCH1. It was 1 710 bp in size. The objective band was identified by double enzyme digestion. DNA sequence showed that UreB was in the correct open reading frame. The sequence comparison analysis showed that DNA and amino acid sequence identities of UreB gene with other strains were 98%. The sequence of UreB of H. pylori strain GZCH1 was submitted to GenBank （accession number： FJ455126）. Conclusions UreB of H. pylori strain GZCH1 is successfully cloned to pGEX-4T-I, which provides a basis for research of oral H. pylori vaccine.