Bertram P A, Schmitz R A, Linder D, Thauer R K
Max-Planck-Institut für Terrestrische Mikrobiologie, Marburg, Germany.
Arch Microbiol. 1994;161(3):220-8. doi: 10.1007/BF00248696.
Methanobacterium thermoautotrophicum (strain Marburg) was found to grow on media supplemented with tungstate rather than with molybdate. The Archaeon then synthesized a tungsten iron-sulfur isoenzyme of formylmethanofuran dehydrogenase. The isoenzyme was purified to apparent homogeneity and shown to be composed of four different subunits of apparent molecular masses 65 kDa, 53 kDa, 31 kDa, and 15 kDa and to contain per mol 0.4 mol tungsten, < 0.05 mol molybdenum, 8 mol non-heme iron, 8 mol acid-labile sulfur and molybdopterin guanine dinucleotide. Its molecular and catalytic properties were significantly different from those of the molybdenum isoenzyme characterized previously. The two isoenzymes also differed in their metal specificity: the active molybdenum isoenzyme was only synthesized when molybdenum was available during growth whereas the active tungsten isoenzyme was also generated during growth of the cells on molybdate medium. Under the latter conditions the tungsten isoenzyme was synthesized containing molybdenum rather than tungsten.
发现嗜热自养甲烷杆菌（马尔堡菌株）能在添加钨酸盐而非钼酸盐的培养基上生长。该古菌随后合成了一种甲酰基甲烷呋喃脱氢酶的钨铁硫同工酶。该同工酶被纯化至表观均一，并显示由表观分子量分别为65 kDa、53 kDa、31 kDa和15 kDa的四种不同亚基组成，每摩尔含有0.4摩尔钨、<0.05摩尔钼、8摩尔非血红素铁、8摩尔酸不稳定硫和钼蝶呤鸟嘌呤二核苷酸。其分子和催化特性与先前表征的钼同工酶显著不同。这两种同工酶在金属特异性方面也有所不同：活性钼同工酶仅在生长过程中有钼时才合成，而活性钨同工酶在细胞在钼酸盐培养基上生长时也会产生。在后一种条件下，合成的钨同工酶含有钼而非钨。
