Structural studies on Mycobacterium tuberculosis RecA: Molecular plasticity and interspecies variability.

Structures of crystals of Mycobacterium tuberculosis RecA, grown and analysed under different conditions, provide insights into hitherto underappreciated details of molecular structure and plasticity. In particular, they yield information on the invariant and variable features of the geometry of the P-loop, whose binding to ATP is central for all the biochemical activities of RecA. The strengths of interaction of the ligands with the P-loop reveal significant differences. This in turn affects the magnitude of the motion of the ‘switch’ residue, Gln195 in M. tuberculosis RecA, which triggers the transmission of ATP-mediated allosteric information to the DNA binding region. M. tuberculosis RecA is substantially rigid compared with its counterparts from M. smegmatis and E. coli, which exhibit concerted internal molecular mobility. The interspecies variability in the plasticity of the two mycobacterial proteins is particularly surprising as they have similar sequence and 3D structure. Details of the interactions of ligands with the protein, characterized in the structures reported here, could be useful for design of inhibitors against M. tuberculosis RecA.

Progress in Protein-protein Docking Approaches / 生物化学与生物物理进展

Protein-protein interactions and recognition are the focal and hot themes of the life science field in the 21st century. Molecular docking approach is the effective computer modeling technology in the study of this topic. Generally, the protein-protein docking procedure is composed of four stages: searching of the binding modes of the receptor and the ligand, filtering of docked modes to eliminate the irrational docked structures, optimizing the structures, evaluating the docked modes with the refined scoring function and ranking them to obtain the near-native structures. Combining the research group's works, in terms of the international and national progress of protein-protein docking approaches, the detailed review was made about the four stages mentioned above. Additionally, the existing major questions are analyzed and the prospects of the future study are made.