Dissecting the functional role of key residues in triheme cytochrome PpcA: a path to rational design of G. sulfurreducens strains with enhanced electron transfer capabilities.

ABSTRACT: PpcA is the most abundant member of a family of five triheme cytochromes c7 in the bacterium Geobacter sulfurreducens (Gs) and is the most likely carrier of electrons destined for outer surface during respiration on solid metal oxides, a process that requires extracellular electron transfer. This cytochrome has the highest content of lysine residues (24%) among the family, and it was suggested to be involved in e-/H(+) energy transduction processes. In the present work, we investigated the functional role of lysine residues strategically located in the vicinity of each heme group. Each lysine was replaced by glutamine or glutamic acid to evaluate the effects of a neutral or negatively charged residue in each position. The results showed that replacing Lys9 (located near heme IV), Lys18 (ne

SUBMITTER: Morgado L 

PROVIDER: S-EPMC4143306 | biostudies-literature | 2014

REPOSITORIES: biostudies-literature