The crystal structure of an uncharacterized protein TTHA0061 from Thermus thermophilus HB8, was determined and refined to 1.8 A by a single wavelength anomalous dispersion (SAD) method. The structural analysis and comparison of TTHA0061 with other existing structures in the Protein Data Bank (PDB) revealed a novel fold, suggesting that this protein may belong to a translation initiation factor or ribosomal protein family. Differential scanning calorimetry analysis suggested that the thermostability of TTHA0061 increased at pH ranges of 5.8-6.2, perhaps due to the abundance of glutamic acid residues. (C) 2010 Elsevier Inc. All rights reserved.