“…This versatile superfamily is a classic example of divergent evolution wherein the proteins have similar overall structures but diverge greatly in their functions. 42,51 Several crystal structures for NTF2-like superfamily proteins were reported, of which the functions have been characterized, including the association domain of CaMKII from mouse (PDB entry 1HKX), 48 NTF2 from rat (PDB entry 1OUN), 52 ketosteroid isomerase (KSI) from Pseudomonas putida (PDB entry 1OPY), 43 scytalone dehydatase ( mg SD) from Magnaporthe grisea (PDB entry 1STD), 44 and polyketide cyclases SnoaL from Streptomyces avidinii (PDB entry 1SJW) 45 and Tcm ARO/CYC from Streptomyces glaucescens (PDB entry 2RER). 46 Despite low amino acid sequence identities, ranging from 9.8% to 17.5%, SgcJ was found to share similar folds with each of the NTF2-like superfamily proteins listed, with rmsds of 3.0, 2.6, 2.7, 2.7, 3.1, and 3.0 Å for the Cα atoms, respectively (Fig.…”