Dernedde J, Eitinger M, Friedrich B
Institut für Pflanzenphysiologie und Mikrobiologie der Freien Universität Berlin, Germany.
Arch Microbiol. 1993;159(6):545-53. doi: 10.1007/BF00249034.
In Alcaligenes eutrophus H16 a pleiotropic DNA-region is involved in formation of catalytically active hydrogenases. This region lies within the hydrogenase gene cluster of megaplasmid pHG1. Nucleotide sequence determination revealed five open reading frames with significant amino acid homology to the products of the hyp operon of Escherichia coli and other hydrogenase-related gene products of diverse organisms. Mutants of A. eutrophus H16 carrying Tn5 insertions in two genes (hypB and hypD) lacked catalytic activity of both soluble (SH) and membrane-bound (MBH) hydrogenase. Immunological analysis showed that the mutants contained SH- and MBH-specific antigen. Growing the cells in the presence of 63Ni2+ yielded significantly lower nickel accumulation rates of the mutant strains compared to the wild-type. Analysis of partially purified SH showed only traces of nickel in the mutant protein suggesting that the gene products of the pleiotropic region are involved in the supply and/or incorporation of nickel into the two hydrogenases of A. eutrophus.
在嗜中性产碱菌H16中，一个多效性DNA区域参与了具有催化活性的氢化酶的形成。该区域位于大质粒pHG1的氢化酶基因簇内。核苷酸序列测定揭示了五个开放阅读框，它们与大肠杆菌hyp操纵子的产物以及不同生物体中其他与氢化酶相关的基因产物具有显著的氨基酸同源性。在嗜中性产碱菌H16中，在两个基因（hypB和hypD）中携带Tn5插入的突变体缺乏可溶性（SH）和膜结合（MBH）氢化酶的催化活性。免疫分析表明，这些突变体含有SH和MBH特异性抗原。与野生型相比，在63Ni2+存在下培养细胞时，突变菌株的镍积累率显著降低。对部分纯化的SH的分析表明，突变蛋白中仅含有微量镍，这表明多效性区域的基因产物参与了镍向嗜中性产碱菌的两种氢化酶中的供应和/或掺入。
