摘要
采用强迫克隆的方法，构建含Ａ．ｃａｕｌｉｎｏｄａｎｓ５～７ｋｂＥｃｏＲⅠ酶切片段的质粒库，以Ｂ．ｊａｐｏｎｉｃｕｍ的ｈｕｐ结构基因为探针，经原位杂交，筛选到带有Ａ．ｃａｕｌｉｎｏｄａｎｓ６．０ｋｂＥｃｏＲⅠ酶切片段的阳性克隆。经三亲本杂交，将阳性克隆转入Ａ．ｃａｕｌｉｎｏｄａｎｓＨｕｐ－突变株中，所得转移接合子的吸氢酶和固氮酶活性均未恢复，表明所克隆到的基因虽与Ｂ．ｊａｐｏｎｉｃｕｍ的ｈｕｐ结构基因同源，却不是一个能完整表达吸氢酶活性的功能单位。
A plasmid library with 5 7 kb EcoR Ⅰ DNA fragments of A. caulinodans was constructed by forcing clone method. Using B. japonicum hup structural genes as probe, the positive clones containing A. caulinodans 6.0 kb EcoR Ⅰ DNA fragments were isolated. Tri parental mating experiments were conducted with recipient strains R 49 and R 309 (Hup - mutants), positive clones as donors and helper plasmid pRK2031, the hydrogenase activity and nitrogenase activity of those transconjugants were not restored. It indicated that the cloned gene from A. caulinodans genomic DNA was homologous although with B. japonicum hup structural gene, they were not a complete function unit for expressing up take hydrogenase activity in A. caulinodans .
出处
《南京农业大学学报》
CAS
CSCD
北大核心
1998年第3期47-52,共6页
Journal of Nanjing Agricultural University
