Isolation and characterization of a N,N'-dicyclohexylcarbodiimide-resistant mutant of Methanothermobacter thermautotrophicus with alterations to the ATP synthesis machinery.
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.
Nováková
Z
Z
Institute of Animal Biochemistry and Genetics, Slovak Academy of Sciences, Ivanka pri Dunaji, Slovakia.
Majerník
A I
AI
Bobál'ová
J
J
Vidová
M
M
Smigán
P
P
D000255:Adenosine Triphosphate / Q000378:metabolism*; D019843:Archaeal Proteins / Q000096:biosynthesis; D004024:Dicyclohexylcarbodiimide / Q000633:toxicity*; D004351:Drug Resistance; D004591:Electrophoresis, Polyacrylamide Gel; D004791:Enzyme Inhibitors / Q000633:toxicity*; D015870:Gene Expression; D008697:Methane / Q000378:metabolism; D017013:Methanobacteriaceae / Q000737:chemistry / Q000187:drug effects* / Q000302:isolation & purification / Q000378:metabolism; D009154:Mutation; D010084:Oxidation-Reduction; D006180:Proton-Translocating ATPases / Q000096:biosynthesis; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D015854:Up-Regulation
D019843:Archaeal Proteins; D004791:Enzyme Inhibitors; D004024:Dicyclohexylcarbodiimide; D000255:Adenosine Triphosphate; D006180:Proton-Translocating ATPases; D008697:Methane