Effects of molybdate and tungstate on the genes expression levels and biochemical characteristics of formate dehydrogenases produced by Desulfovibrio alaskensis NCIMB 3 13491.

CRISTIANO S. MOTA; ODILE VALETTE; PABLO J. GONZÁLEZ; CARLOS D. BRONDINO; JOSÉ J. G. MOURA,; ISABEL MOURA; ALAIN DOLLA; MARÍA G. RIVAS

JOURNAL OF BACTERIOLOGY

AMER SOC MICROBIOLOGY

Año: 2011 vol. 193 p. 2917 - 2923

0021-9193

Formate dehydrogenases (Fdh) are enzymes that catalyze the formate oxidation to carbon dioxide and that contain either Mo or W in a mononuclear form in the active site. In the present work the influence of Mo and W salts on the production of Fdh by Desulfovibrio alaskensis NCIMB 13491 was studied. Two different Fdhs, one containing W (W-Fdh) and a second Fdh incorporating either Mo or W (Mo/W-Fdh), were purified. Both enzymes were isolated from cells grown in a medium supplemented with 1 μM molybdate, whereas only the W-Fdh was purified from cells cultured in medium supplemented with 10 μM tungstate. We demonstrated that the genes encoding the Mo/W-Fdh are strongly down-regulated by W and slightly up-regulated by Mo. Metal effects on the expression level of the genes encoding the W-Fdh were less significant. Furthermore, the expression levels 1 of the genes encoding proteins involved in molybdate and tungstate transport are down-regulated under the experimental conditions evaluated in this work. The molecular and biochemical properties of these enzymes and the selective incorporation of either Mo or W are discussed.