The molecular structure of a protein commandeered by HIV to enter human cells reveals sites that could lead to better anti-HIV drugs.

The protein CCR5 resides on the surface of certain immune cells. A team led by Beili Wu at the Chinese Academy of Sciences' Shanghai Institute of Materia Medica successfully crystallized CCR5 bound to the anti-HIV drug maraviroc. The structure suggests that the drug works by making CCR5 more rigid, and so prevents movements that allow HIV to enter cells. It also reveals why such HIV drugs fail to work with certain CCR5 mutants.

Differences between CCR5 and CXCR4, another protein used by HIV to enter cells, may explain why some HIV strains favour one protein gateway over the other.

Science http://doi.org/ntj (2013)