Crystal structure of Mycobacterium tuberculosis SecA, a preprotein translocating ATPase

AUTOR(ES)

Sharma, Vivek

FONTE

The National Academy of Sciences

RESUMO

In bacteria, the majority of exported proteins are translocated by the Sec system, which recognizes the signal sequence of a preprotein and uses ATP and the proton motive force to mediate protein translocation across the cytoplasmic membrane. SecA is an essential protein component of this system, containing the molecular motor that facilitates translocation. Here we report the three-dimensional structure of the SecA protein of Mycobacterium tuberculosis. Each subunit of the homodimer contains a “motor” domain and a translocation domain. The structure predicts that SecA can interact with the SecYEG pore and function as a molecular ratchet that uses ATP hydrolysis for physical movement of the preprotein. Knowledge of this structure provides a framework for further elucidation of the translocation process.

Documentos Relacionados

• The SecA and SecY subunits of translocase are the nearest neighbors of a translocating preprotein, shielding it from phospholipids.
• Regulation of the Escherichia coli secA gene by protein secretion defects: analysis of secA, secB, secD, and secY mutants.
• In vivo cross-linking of the SecA and SecY subunits of the Escherichia coli preprotein translocase.
• The SecA Subunit of Escherichia coli Preprotein Translocase Is Exposed to the Periplasm
• A large conformational change of the translocation ATPase SecA