Kim K Y, Jordan D, Krishnan H B
Department of Plant Pathology, University of Missouri, Columbia 65211, USA.
FEMS Microbiol Lett. 1998 Feb 1;159(1):121-7. doi: 10.1111/j.1574-6968.1998.tb12850.x.
Rahnella aquatilis is a Gram-negative bacterium that can fix atmospheric nitrogen and also has the ability to solubilize mineral phosphate. We have cloned the genes that confer the mineral phosphate solubilizing (Mps) trait from this organism by mobilizing a cosmid library of R. aquatilis into Escherichia coli HB101. A 7.0-kb EcoRI fragment from a cosmid, when transferred into E. coli strains HB101 and DH5 alpha, conferred the ability to solubilize hydroxyapatite and the production of gluconic acid to E. coli. The relative amounts of soluble phosphate and gluconic acid produced by the cloned 7.0-kb EcoRI fragment in E. coli were significantly higher than those of R. aquatilis. Nucleotide sequence analysis revealed two complete open reading frames (ORF1 and ORF2) and a partial ORF, ORF1 and ORF2 encoded proteins of molecular mass 10 kDa and 44 kDa. The 44-kDa protein showed extensive sequence similarity to pqqE of Erwinia herbicola, Klebsiella pneumoniae and A. Acinetobacter calcoaceticus. The 10-kDa protein revealed strong similarity to the pqqD of K. pneumoniae and A. calcoaceticus.
水生拉恩氏菌是一种革兰氏阴性菌，它能够固定大气中的氮，并且具有溶解矿物磷酸盐的能力。我们通过将水生拉恩氏菌的黏粒文库转入大肠杆菌HB101，克隆了赋予该菌溶解矿物磷酸盐（Mps）特性的基因。来自一个黏粒的7.0 kb EcoRI片段，当转入大肠杆菌菌株HB101和DH5α时，赋予了大肠杆菌溶解羟基磷灰石的能力以及产生葡萄糖酸的能力。在大肠杆菌中，由克隆的7.0 kb EcoRI片段产生的可溶性磷酸盐和葡萄糖酸的相对量显著高于水生拉恩氏菌。核苷酸序列分析揭示了两个完整的开放阅读框（ORF1和ORF2）以及一个部分开放阅读框，ORF1和ORF2编码的蛋白质分子量分别为10 kDa和44 kDa。44 kDa的蛋白质与草生欧文氏菌、肺炎克雷伯菌和乙酸钙不动杆菌的pqqE具有广泛的序列相似性。10 kDa的蛋白质与肺炎克雷伯菌和乙酸钙不动杆菌的pqqD具有很强的相似性。
