A₁A_O ATP synthases with a V‐type c subunit have only been found in hyperthermophilic archaea which makes bioenergetic analyses impossible due to the instability of liposomes at high temperatures. A search for a potential archaeal A₁A_O ATP synthase with a V‐type c subunit in a mesophilic organism revealed an A₁A_O ATP synthase cluster in the anaerobic, acetogenic bacterium Eubacterium limosum KIST612. The enzyme was purified to apparent homogeneity from cells grown on methanol to a specific activity of 1.2 U·mg⁻¹ with a yield of 12%. The enzyme contained subunits A, B, C, D, E, F, H, a , and c . Subunit c is predicted to be a typical V‐type c subunit with only one ion (Na⁺)‐binding site. Indeed, ATP hydrolysis was strictly Na⁺‐dependent. N ,N ′‐dicyclohexylcarbodiimide (DCCD) inhibited ATP hydrolysis, but inhibition was relieved by addition of Na⁺. Na⁺ was shown directly to abolish binding of the fluorescence DCCD derivative, NCD‐4, to subunit c , demonstrating a competition of Na⁺ and DCCD/NCD‐4 for a common binding site. After incorporation of the A₁A_O ATP synthase into liposomes, ATP‐dependent primary transport of ²²Na⁺ as well as ΔµNa⁺‐driven ATP synthesis could be demonstrated. The Na⁺ A₁A_O ATP synthase from E. limosum is the first ATP synthase with a V‐type c subunit from a mesophilic organism. This will enable future bioenergetic analysis of these unique ATP synthases.

中文翻译：

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在嗜温细菌中具有V型c亚基的Na + A1 AO ATP合酶。

仅在超嗜热古细菌中发现具有V型c亚基的₁ A _O ATP合成酶，由于脂质体在高温下不稳定，因此无法进行生物能分析。一种用于潜在古细菌甲搜索₁甲_ö ATP与V型合酶Ç在嗜温生物亚基揭示的A ₁甲_ö ATP合酶集群中的厌氧的，产乙酸细菌真杆菌limosum KIST612。从在甲醇中生长至比活度为1.2 U·mg ^-1的细胞中纯化出的酶具有明显的均质性收率为12％。该酶包含亚基A，B，C，D，E，F，H，a和c。c亚基被预测为典型的V型c亚基，只有一个离子（Na ⁺）结合位点。确实，ATP水解严格依赖于Na ⁺依赖。N，N'-二环己基碳二亚胺（DCCD）抑制ATP水解，但通过添加Na ⁺解除了抑制作用。直接显示Na ⁺消除了荧光DCCD衍生物NCD-4与c亚基的结合，表明Na ⁺的竞争和DCCD / NCD-4（用于共同的结合位点）。将A ₁ A _O ATP合酶掺入脂质体后，可以证明ATP依赖的²² Na ⁺初级转运以及ΔµNa ⁺驱动的ATP合成。源自E. limosum的Na ⁺ A ₁ A _O ATP合酶是嗜温生物中具有V型c亚基的第一个ATP合酶。这将使将来能够对这些独特的ATP合酶进行生物能分析。