Institute of Animal Biochemistry and Genetics, Slovak Academy of Sciences, Ivanka pri Dunaji, Slovakia.
Folia Microbiol (Praha). 2009 Nov;54(6):483-6. doi: 10.1007/s12223-009-0068-8. Epub 2010 Feb 7.
A spontaneous mutant of Methanothermobacter thermautotrophicus resistant toward the ATP-synthase inhibitor N,N'-dicyclohexylcarbodiimide (DCCD) was isolated. DCCD normally inhibits methanogenic electron-transport-driven ATP synthesis, however, the DCCD-resistant strain exhibited methanogenesis in the presence of 300 micromol/L DCCD. Total ATP synthesis was shown to be higher in the mutant strain, both in the presence and absence of DCCD. These results suggested a modification in the ATP-synthesizing system of the mutant strain. Using Blue Native PAGE combined with MALDI TOF/TOF mass spectrometry, increased concentrations of both the A(1) and A(o) subcomplexes of the A(1)A(o)-type synthase were identified in the mutant strain. However, no alterations were found in the structural genes (atp) for the A(1)A(o) ATP synthase. The results imply that DCCD resistance is a consequence of increased A(1)A(o) ATP synthase expression, and suggest that genes involved in regulating synthase expression are responsible for DCCD resistance.
一株对 ATP 合酶抑制剂 N,N'-二环己基碳二亚胺（DCCD）具有抗性的产甲烷热原体自发突变株被分离出来。DCCD 通常会抑制甲烷生成过程中电子传递驱动的 ATP 合成，但该 DCCD 抗性菌株在存在 300µmol/L DCCD 的情况下仍能进行甲烷生成。研究表明，突变株的总 ATP 合成在有和没有 DCCD 的情况下都更高。这些结果表明突变株的 ATP 合成系统发生了修饰。使用 Blue Native PAGE 结合 MALDI TOF/TOF 质谱分析，在突变株中鉴定到 A(1)A(o)-型合酶的 A(1)和 A(o)亚基复合物的浓度增加。然而，在 A(1)A(o)ATP 合酶的结构基因(atp)中没有发现任何改变。这些结果表明，DCCD 抗性是由于 A(1)A(o)ATP 合酶表达增加所致，并表明参与调节合酶表达的基因是导致 DCCD 抗性的原因。
