Crystallization and X-Ray Diffraction Studies of Salmonella Invasion Protein D (SipD), Insight Tip Component of Salmonella typhi Type III Secretion System

Abstract

Many pathogenic gram-negative bacteria including Salmonella typhi utilize type III secretion systems (T3SSs) to inject bacterial proteins into host cells and to initiate infections. One of the essential components of the T3SS is the tip protein known as SipD, translocon component via the type III secretion system SPI-1. Here, recombinant SipD is produced and crystallized; the details of cloning, expression, and crystallization are reported. Crystals of SipD are obtained by sitting-drop vapour diffusion method. X-ray diffraction data are collected up to 3.8 Å resolution. Single crystals belong to the monoclinic sp. gr. P2; unit-cell parameters: a = 70.86, b = 103.70, c = 89.28 Å, β = 107.63°.