Protein Meta-Functional Signatures from Combining Sequence, Structure, Evolution, and Amino Acid Property Information
Figure 4
The application of MFS to understand the role of btuba/btubb dimer in the bacterial genus Prosthecobacter using the predicted and experimental structures.
Both structures are colored by depicting higher MFS scoring residues with a more intense red color, with the top-10 high-scoring residues represented by spheres. One GTP and one GDP in the predicted structure, as well as one GDP and two SO42− ions in the experimental structure are shown as yellow spheres. The predicted structure is generated by homology-modeling techniques using the eukaryotic α/β tubulin dimer (PDB identifier: 1jff) as the template. The taxol ligand and metal ions are omitted from the predicted structure for easier depiction. In the predicted structure, btubb lies above btuba, with a GDP molecule enclosed by the dimer interface. In the experimental structure (PDB identifier: 2btq), btuba lies above btubb and there is no GDP in the dimer interface. Our MFS analysis first confirmed that btuba and btubb indeed form dimers due to the existence of a high-scoring cluster in their dimer interface, in contrast to previous predictions made by using the structural stability score alone. In addition, the MFS suggests that regardless of how btuba and btubb orient with each other, their interface is functionally important and may bind to GDP molecules.