The target of RNAIII-activating protein (TRAP) from Staphylococcus aureus:: purification, crystallization and preliminary X-ray analysis

The target of the RNAIII-activating protein (TRAP) is a 21 kDa protein in which phosphorylation is activated by the RNAIII-activating protein (RAP), which causes an increase in RNAII and RNAIII synthesis and the production of the virulence factors. In an attempt to examine the structural role of TRAP in the signal transduction pathway, TRAP from Staphylococcus aureus was overexpressed, purified and crystallized using PEG 8000 and 5% Jeffamine M600 (pH 7.0), as precipitants by hanging-drop vapour diffusion methods at 287 K. The crystals belong to the orthorhombic space group, P2(1)2(1)2(1), with unit cell parameters of a=39.68, b=50.41, c=85.45 A. There is one monomer of TRAP per crystallographic asymmetric unit with a crystal volume per protein mass (V-M) of 2.06 angstrom(3) Da(-1) and a solvent content of 40.3%. A complete data set diffracting to 1.9 angstrom resolution was collected from a single crystal at 100 K using a synchrotron-radiation source. (c) 2004 Elsevier B.V. All rights reserved.