The crystal structure of MJ0577, a "hypothetical protein" from Methanoccocus jannaschii, which has no sequence similarities to any proteins of known functions. The structure revealed a new protein fold and a new ATP binding motif. Biochemical tests of its molecular function inferred by the structure suggest that the protein is a molecular switch that hydrolyzes ATP in the presence of its partner proteins.

BSGC Role

Sung-Hou Kim is the principal investigator of the BSGC. He will be coordinating the entire project and overseeing the Component Project III involving the structure determination of the proteins purified by Component II by X-ray crystallographic methods.

Component Project Information

Analysis of several genomic sequences indicates that no known functions can be assigned to a significant fraction of the genes. Since the molecular (biochemical and biophysical) function of a gene product is tightly coupled to its three-dimensional structure, finding the structure or its folding pattern may provide important insight into the molecular function of the gene product. That, in turn, may help in understanding its cellular function (networks of many molecular functions) as well. We propose to construct a comprehensive structural representation of most of the gene products of two of the simplest minimal organisms, the human pathogens Mycoplasma genitalium and Mycoplasma pneumoniae. We do this by determining the three-dimensional structures by X-ray crystallography of the fold representatives of most of the proteins in these organisms or their homologs from other organisms. The structures will be computationally analyzed, and, when the structures implicate possible molecular functions, they will be tested experimentally. These molecular functions and structural information will be correlated with the cellular function of the gene products. Furthermore, we plan to map these structures on a global protein fold space to understand the structural phylogeny.