Determination of the magnetic properties and orientation of the heme axial ligands of PpcA from Geobacter metallireducens by paramagnetic NMR.

Determination of the magnetic properties and orientation of the heme axial ligands of PpcA from Geobacter metallireducens by paramagnetic NMR. J Inorg Biochem. 2019 May 17;198:110718 Authors: Fernandes TM, Morgado L, Salgueiro CA, Turner DL Abstract The rising interest in the use of Geobacter bacteria for biotechnological applications demands a deep understanding of how these bacteria are able to thrive in a variety of environments and perform extracellular electron transfer. The Geobacter metallireducens bacterium can couple the oxidation of a wide range of compounds to the reduction of several extracellular acceptors, including heavy metals, toxic organic compounds or electrode surfaces. The periplasmic c-type cytochrome PpcA from this bacterium is a member of a family composed of five periplasmic triheme cytochromes, which are important to bridge the electron transfer between the cytoplasm and the extracellular environment. To better understand the functional mechanism of PpcA it is essential to obtain structural data for this cytochrome. In this work, the geometry of the heme axial ligands, as well as the magnetic properties of the hemes were determined for the oxidized form of the cytochrome, using the 13C NMR chemical shifts of the heme α-substituents. The results were further compared with those previously obtained for the homologous cytochrome from Geobacter sulfurreducens. The orientations of the axial histidine planes and ...
Source: Journal of Inorganic Biochemistry - Category: Biochemistry Authors: Tags: J Inorg Biochem Source Type: research