Photosystem I reaction center: past and future

Science has always been drawn to uncover fundamental life processes. Photosynthesis is one, if not the most fascinating, of them. Within it, the protein complexes that catalyze light-induced electron transport and photophosphorylation are enchanting creations of evolution. Plant Photosystem I (PS I) is not the largest protein complex in nature but it is the most elaborate in the number of prosthetic groups involved in its fabric. Thirty years ago, one of us (NN) developed a fascination for this complex and, despite the apparent neglect (lack of publications in the last few years), never let it go. Only a crystal structure at 2 A resolution will satiate our curiosity. In this minireview, we trace the past, and end the article with a comment on future prospects. For the present situation, see Parag Chitnis (2001).