Tani K, Watanabe T, Matsuda H, Nasu M, Kondo M
Department of Environmental Science and Microbiology, Osaka University, Japan.
Microbiol Immunol. 1996;40(2):99-105. doi: 10.1111/j.1348-0421.1996.tb03323.x.
The germination mutant TM-31 of Bacillus megaterium ATCC 12872, was isolated by transposon Tn917 insertional mutagenesis. Glucose, L-proline, L-leucine and KNO3 germinated TM-31 poorly. The DNA in the region of the Tn917 insertion was cloned, and its nucleotide sequence determined. One major open reading frame was present on the cloned DNA. The hydrophobic protein encoded is presumably membrane-associated. A homology search revealed that the gene encoded in the region of the Tn917 insertion is homologous to napA of Enterococcus hirae. napA codes for the NaH-antiporter. It is hypothesized that transport of cations must play an important role in spore germination in B. megaterium ATCC 12872.
巨大芽孢杆菌ATCC 12872的萌发突变体TM-31是通过转座子Tn917插入诱变分离得到的。葡萄糖、L-脯氨酸、L-亮氨酸和KNO₃对TM-31的萌发效果不佳。克隆了Tn917插入区域的DNA，并测定了其核苷酸序列。克隆的DNA上存在一个主要的开放阅读框。所编码的疏水蛋白可能与膜相关。同源性搜索显示，Tn917插入区域编码的基因与希拉肠球菌的napA同源。napA编码Na⁺/H⁺反向转运蛋白。据推测，阳离子转运在巨大芽孢杆菌ATCC 12872的孢子萌发中必定起着重要作用。
