This entry represents the PccH protein, a unique cytochrome c (GSU3274) found in Geobacter sulfurreducens. PccH is a small (15 kDa) cytochrome that contains a single c-type heme and plays an essential role in electron transfer from graphite electrode ...
This entry represents the PccH protein, a unique cytochrome c (GSU3274) found in Geobacter sulfurreducens. PccH is a small (15 kDa) cytochrome that contains a single c-type heme and plays an essential role in electron transfer from graphite electrodes to fumarate, the terminal electron acceptor, in G. sulfurreducens. The crystal structure of PccH, reveals a distinct fold characterized by two lobes with the heme located in a cleft between them. Notably, PccH exhibits a low reduction potential of -24 mV at pH 7, which is unusual for monoheme cytochromes. Based on structural and phylogenetic analyses, PccH represents a novel subclass of class I monoheme cytochromes. The unique structural features and low reduction potential of PccH likely enable its redox activity within the typically negative potential range encountered by G. sulfurreducens. Although located in the periplasm, PccH is not involved in the initial electron transfer from the electrode but is believed to participate in downstream electron transport events in the periplasm [1].
