Isolation, purification and preliminary X-ray characterization of Cpn60-2 (65 kDa heat-shock protein) from Mycobacterium tuberculosis

Cpn60-2 is a member of a unique family of putative molecular chaperones homologous to GroEL (Cpn60) but of unknown function and found only in Mycobacterium tuberculosis and closely related species. Cpn60-2 has mainly been studied for its strong immunogenity. Here, the purification, crystallization and preliminary crystallographic analysis of M. tuberculosis Cpn60-2 are reported. The crystals belong to space group P2, with unit-cell parameters a = 57, b = 115.5, c = 81.5 Å, β = 95.5°, and contain a dimer in the asymmetric unit. The crystals diffract to 4.0 Å using a Cu rotating-anode X-ray generator.