Chapter 15 Molecular Recognition in NADPH-Dependent Plant Thioredoxin Systems—Catalytic Mechanisms, Structural Snapshots and Target Identifications

Abstract NADPH-dependent thioredoxin systems (NTS) control enzymatic activities and provide reducing equivalents to metabolic pathways in all types of organisms, from bacteria to mammals. In these redox systems, thioredoxin reduces disulfide bonds in target proteins and receives electrons from NADPH via thioredoxin reductase (NTR). Plant NTS were first discovered in wheat seeds some 30 years ago and were demonstrated to play a key role in the seed germination process. Since then, NTS have been identified in a large variety of photosynthetic organisms, and an organelle-specific pattern for their cellular localization is established. The last decade has witnessed a remarkable expansion of the knowledge about these systems and novel molecular architectures, catalytic mechanisms and target proteins have been revealed. In general, these findings have provided a wealth of information about the physiological role and molecular mechanisms of plant NTS, and this chapter will highlight some of the recent developments in this area.