An updated structural classification of substrate-binding proteins

Substrate-binding proteins (SBPs) play an important role in solute uptake and signal transduction. In 2010 Berntsson et al. classified the 114 organism-specific SBP structures available at that time and defined six protein clusters, based on their structural similarity. Since then the number of unique SBP structures has increased almost 5-fold, whereas the number of protein entries in the Protein Data Bank (PDB) nearly doubled. On the basis of the much larger dataset, we now sub-classify the SBPs within the original clusters. Moreover, we propose a 7(th) cluster based on a small group of SBPs with structural features significantly different from those observed in the other proteins. This article is protected by copyright. All rights reserved.