Systematic fold recognition analysis of the sequences encoded by the genome of Mycoplasma pneumoniae

A robust tool for fold recognition was applied to the systematic analysis of the sequences below 200 residues encoded by the genome of Mycoplasma pneumoniae. The goal was to determine the additional information gain achievable in genome analysis by fold recognition, beyond the intrinsic limits of homology studies. A list of 124 sequences encoding for soluble proteins or domains not homologous to each other, or to proteins with known three-dimensional structure, was analyzed, resulting in significant Z scores for the energy of the structural models in 12 of these cases. This result indicates that systematic application of fold recognition techniques to the analysis of structurally unassigned soluble proteins can lead to high-confidence structural predictions with an efficiency of about 10%, a relevant contribution besides the complementary approach of homology analysis. Four of the predictions presented include mapping of the putative active site of the target sequence and lead to the detection of probable catalytic and binding residues. The data are discussed with reference to the functional implications of the structural models and to the results reported for the homologous genome of Mycoplasma genitalium.