Structural basis of the binding of fatty acids to peptidoglycan recognition protein, PGRP-S through second binding site

► PGRP-S belongs to innate immune system and provides the first line of defense. ► Structure of camel PGRP-S forms a linear chain polymer with two unique contacts. ► It is found that fatty acids including mycolic acid bind at one of these two contacts. ► Structures of the complexes of CPGRP-S with fatty acids revealed a new binding site. ► This indicates that CPGRP-S may play a role in the treatment of tuberculosis.