Cross-Species Molecular Docking of Ferredoxin into Photosystem I of T. Elongatus and Synechocystis sp. PCC 6803

Abstract

T. Elongatus and Synechocystis sp. PCC 6803 are commonly used in the study of photosynthesis. The purpose of this research is to study the molecular interactions between the stromal domain (PsaC, D and E) of Photosystem I (PSI) and Ferredoxin (Fd) in a cross-species manner in order to optimize the electron transfer between the stromal domain and ferredoxin. Improving the electron transfer in these proteins should be able to aid in the design of potential biophotovoltaic energy cells for generating green electrical power. Computational models of PSI and Fd from the respective cyanobacterial species were obtained from the Protein Data Bank. The molecular docking software, ClusPro, was used to dock both Fd proteins into each stromal domain of PSI from T. Elongatus and Synechocystis sp. PCC 6803. 30 cluster centers were obtained and the amino acid residue contacts at the protein-protein interface were analyzed to determine which residues are important to binding. The results suggest that high affinity protein-protein structures are possible and the electron transfer distance can be improved when docking Fd from one species to another.