EVOLUTIONARY, MECHANISTIC, AND PREDICTIVE ANALYSES OF THE HYDROXYMETHYLDIHYDROPTERIN PYROPHOSPHOKINASE FAMILY OF PROTEINS

Abstract A prediction has been prepared ab initio for the secondary structure of the hydroxymethyldihydropterin pyrophosphokinase (HPPK) family of proteins starting from a set of aligned homologous protein sequences. Attempts to identify a fold by threading failed, judging by the inability to find a threading “hit” that had a secondary structure that was plausibly congruent to the predicted secondary structure for the HPPK family. Therefore, a set of tertiary structure models was assembled ab initio, where alternative models were built and used to select between alternative secondary structure models. This prediction report illustrates the importance of non-computational approaches to structure prediction at its present frontier, which is to obtain medium resolution models of tertiary structure.