INVESTIGADORES
RAPISARDA Viviana Andrea
congresos y reuniones científicas
Título:
Enzymatic activity of a Escherichia coli NDH-2 mutant lacking the carboxi-terminal region.
Autor/es:
VILLEGAS J. M.; VOLENTINI S. I.; FARIAS R. N.; RODRIGUEZ MONTELONGO L.; RAPISARDA V. A.
Lugar:
Rosario
Reunión:
Congreso; XLII ReuniĆ³n Anual de SAIB; 2006
Institución organizadora:
SAIB
Resumen:
NADH dehydrogenase-2 (NDH-2) of Escherichia coli is a membrane flavoprotein with cupric-reductase activity. By bioinformatics, we proposed four functional domains in NDH-2, one of them, domain IV, could be involved in the enzyme anchorage to the membrane. However, other authors have proposed that this interaction could occur by multiple anphipatic turns along the enzyme. The aims of this work was to obtain a mutant protein without the carboxi-terminal region or domain IV and to analyze the effects over NDH-2 enzymatic activities. We used a NADH dehydogenase deficient strain complemented with either the wild-type ndh gene or the mutant one. The results obtained with all the cellular fractions tested showed that the enzyme without carboxi-terminal region was less active respect the wild-type enzyme. Furthermore, the NDH-2 mutant was not able to grow in mannitol as it was described for NADH dehydrogenase null mutants. Our results suggest that the carboxi-terminal region of NDH-2 could be implicated in its enzymatic activities. The lack of activity could be caused by abnormal cellular localization and improper interaction with quinones.