Crystallization and X-ray crystallographic studies of wild-type and mutant tryptophan synthase alpha-subunits from Escherichia coli
Jeong, M.Suk.; Jang, S.Bok.
Molecules and Cells 19(2): 219-222
ISSN/ISBN: 1016-8478 PMID: 15879705 Accession: 011912773
The alpha-subunit of Escherichia coli tryptophan synthase (alpha TS), a component of the tryptophan synthase alpha(2)beta(2) complex, is a monomeric 268-residues protein (Mr = 28,600). alpha TS by itself catalyzes the cleavage of indole-3-glycerol phosphate to glyceraldehyde-3-phosphate and indole, which is converted to tryptophan in tryptophan biosynthesis. Wild-type and P28L/Y173F double mutant alpha-subunits were overexpressed in E. coli and crystallized at 298 K by the hanging-drop vapor-diffusion method. X-ray diffraction data were collected to 2.5 angstrom resolution from the wild-type crystals and to 1.8 angstrom from the crystals of the double mutant, since the latter produced better quality diffraction data.