Synthesis of a Klebsiella pneumoniae O-antigen heteropolysaccharide (O12) requires an ABC 2 transporter
Synthesis of a Klebsiella pneumoniae O-antigen heteropolysaccharide (O12) requires an ABC 2 transporter
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DOI：
10.1128/jb.185.5.1634-1641.2003
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发表时间：
2003-03-01
影响因子：
3.2
通讯作者：
Tomás, JM
中科院分区：
文献类型：
--
作者：
Izquierdo, L;Merino, S;Tomás, JM
我们将肺炎克雷伯菌KT776(O12：K80)的粘粒基因组文库导入到大肠杆菌DH5pha中进行血清抗性筛选，发现了一个编码肺炎克雷伯菌O12-抗原脂多糖(LPS)酶的重组克隆。在大肠杆菌K-12中产生肺炎克雷伯菌O12抗原内毒素需要8个开放阅读框(ORF)(WB(O12)基因簇)。对肺炎克雷伯菌WB(O12)群的完整分析表明，从ORF5到ORF8(或WBBL到WBBA)与粘质沙雷氏菌的WB(O4)群有一个有趣的重合。这促使我们产生肺炎克雷伯菌KT776(O12)的突变株，并利用先前获得的粘质链球菌N28b(O4)突变株来研究两个肠杆菌WB簇之间的互补性。这两个WB基因簇都是O-抗原杂多糖的ABC-2转运体依赖的途径的例子。WZM-WZT基因和Wbba或wbbB基因在两个基因簇之间不能互换，尽管它们具有很高的相似性。然而，将三个同源基因(WZM-WZT-WBBA或WZM-WZT-wbbB)导入不能产生O抗原的突变体中，可以产生特定的O抗原。肺炎克雷伯菌O12 WBBL蛋白与粘质链球菌O4的WBBL蛋白在粘质链球菌O4或E.ColiK-12的遗传背景下具有相同的功能。
A recombinant clone encoding enzymes for Klebsiella pneumoniae O12-antigen lipopolysaccharide (LPS) was found when we screened for serum resistance of a cosmid-based genomic library of K pneumoniae KT776 (O12:K80) introduced into Escherichia coli DH5alpha. A total of eight open reading frames (ORFs) (wb(O12) gene cluster) were necessary to produce K pneumoniae O12-antigen LPS in E. coli K-12. A complete analysis of the K. pneumoniae wb(O12) cluster revealed an interesting coincidence with the wb(O4) cluster of Serratia marcescens from ORF5 to ORF8 (or WbbL to WbbA). This prompted us to generate mutants of K. pneumoniae strain KT776 (O12) and to study complementation between the two enterobacterial wb clusters using mutants of S. marcescens N28b (O4) obtained previously. Both wb gene clusters are examples of ABC 2 transporter-dependent pathways for O-antigen heteropolysaccharides. The wzm-wzt genes and the wbbA or wbbB genes were not interchangeable between the two gene clusters despite their high level of similarity. However, introduction of three cognate genes (wzm-wzt-wbbA or wzm-wzt-wbbB) into mutants unable to produce O antigen allowed production of the specific O antigen. The K. pneumoniae O12 WbbL protein performs the same function as WbbL from S. marcescens O4 in either the S. marcescens O4 or E. coli K-12 genetic background.