Structural characterization of the substrate-binding proteins of Mycobacterium tuberculosis
Mammalian-cell-entry (MCE)4-complex

Mycobacterium tuberculosis (Mtb) is a deadly microorganism which causes the development of cavities in the lungs and the impairment of respiratory function leading to the disease tuberculosis. Mtb infection is widespread with nearly one-fourth of the world population latently infected and is responsible for more than a million deaths annually. It has been shown that a protein complex (Mce4) helps in the survival of Mtb inside the lung by importing the cholesterol from human cells. This cholesterol serves as a fuel for providing energy and carbon to Mtb.

Therefore, our aim was to understand the structure and function of the Mce4-cholesterol importer of Mtb. For this, we have characterized the proteins of this complex in detail. The results give the first clues on the probable arrangement of the Mce4 complex in Mtb. In the long-term, these results would help in developing anti-TB drugs targeting the cholesterol uptake of Mtb.