Functional assignment of Mycobacterium tuberculosis proteome revealed by genome-scale fold-recognition

Hundreds of putative enzymes from Mycobacterium tuberculosis as well as other mycobacteria remain categorized as "conserved hypothetical proteins" or "hypothetical proteins", offering little or no information on their functional role in pathogenic and non-pathogenic processes. In this study we have predicted the fold and 3-D structure of more than 99% of all proteins encoded in the genome of M. tuberculosis H37Rv. Fold-recognition, database search, 3-D modelling was performed using Protein Homology/analogy Recognition Engine V 2.0 (Phyre2). These results are used to tentatively assign potential function for unannotated enzymes and proteins. In summary, fold-recognition and structural homology might be used as a complementary tool in genome annotation efforts and furthermore, it can deliver primary sequence-independent information regarding structure, ligands and even substrate specificity for enzymes that display low primary sequence identity with potential homologues in other species.