Crystallization and preliminary X-ray crystallographic analysis of a GroEL1 fragment from Mycobacterium tuberculosis H37Rv

Abstract

Full-length GroEL1 from Mycobacterium tuberculosis H37Rv was cloned, overexpressed and purified. Crystals were obtained by the hanging-drop vapor-diffusion method and contained a 23 kDa GroEL1 fragment. A complete native data set was collected from a single frozen crystal that belonged to the orthorhombic space group P2(1)2(1)2, with unit-cell parameters a = 75.47, b = 78.67, c = 34.89 A, alpha = beta = gamma = 90 degrees , and diffracted to 2.2 A resolution on a home X-ray source.

Figure 1

Cluster of rod-shaped crystals of a M. tuberculosis GroEL1 fragment.

Figure 2

(a) Silver-stained 12% SDS–PAGE gel showing molecular-weight markers (lane 1), purified full-length M. tuberculosis GroEL1 (lane 2) and the crystallization mother liquor (lane 3). The masses of the molecular-weight standards are given in kDa. The arrows indicate full-length GroEL1 (A) and the protein fragments of 43 kDa (B) and 23 kDa (C), respectively. (b) Coomassie-stained 15% SDS–PAGE gel showing molecular-weight markers (lane 1) and trypsin-treated GroEL1 (lane 2). The arrow indicates the 23 kDa fragment.