Flavodiiron oxygen reductase from Entamoeba histolytica: modulation of substrate preference by tyrosine 271 and lysine 53.

ABSTRACT: Flavodiiron proteins (FDPs) are a family of enzymes endowed with bona fide oxygen- and/or nitric-oxide reductase activity, although their substrate specificity determinants remain elusive. After a comprehensive comparison of available three-dimensional structures, particularly of FDPs with a clear preference toward either O2 or NO, two main differences were identified near the diiron active site, which led to the construction of site-directed mutants of Tyr(271) and Lys(53) in the oxygen reducing Entamoeba histolytica EhFdp1. The biochemical and biophysical properties of these mutants were studied by UV-visible and electron paramagnetic resonance (EPR) spectroscopies coupled to potentiometry. Their reactivity with O2 and NO was analyzed by stopped-flow absorption spectroscopy and amperomet

SUBMITTER: Goncalves VL 

PROVIDER: S-EPMC4192481 | biostudies-literature | 2014 Oct

REPOSITORIES: biostudies-literature