Structure of translation initiation factor 1 from Mycobacterium tuberculosis and inferred binding to the 30S ribosomal subunit.

The crystal structure of the free form of IF1 from Mycobacterium tuberculosis has been determined at 1.47 A resolution. The structure adopts the expected OB fold and matches the high structural conservation among IF1 orthologues. In order to further explore the function of Mtb-IF1, we built a model of its interaction with the 30S ribosomal subunit based on the crystal structure of the complex from Thermus thermophilus. The model suggests that several functionally important side chain residues undergo large movements while the rest of the protein in complex shows only very limited conformational change as compared to its form in solution.