Purification, characterization and preliminary X-ray crystallographic studies on Neisseria gonorrhoeae Gly1ORF1

Gly1ORF1 is a protein produced by the two pathogenic Neisseria species, N. gonorrhoeae and N. meningitidis, but not by commensal Neisseria, suggesting that it may be involved in pathogenesis. The protein has a signal sequence that is cleaved, is associated with outer membrane fractions of N. gonorrhoeae (GC) and is found in spent media and in outer-membrane fractions when expressed in Escherichia coli. GC strains with null mutations of the gly1 locus have increased toxicity to human fallopian tubes in organ culture, suggesting that Gly1ORF1 may alter the amount or properties of toxic moieties produced by GC [Arvidson et al. (1999), infect. Immun. 67, 643-652]. In an effort to understand the function of Gly1ORF1 and its role in pathogenesis, structural biology studies have been initiated. Here, the purification, characterization by dynamic light scattering, crystallization and preliminary X-ray crystallographic studies of recombinant Gly1ORF1 are reported. Dynamic light scattering indicated the protein to be a dimer in solution. The crystals belonged to space group P6(3), with unit-cell parameters a = 95.2, b = 95.2, c = 83.7 A and two molecules per asymmetric unit. The crystals diffracted to 2.4 A using a conventional X-ray source.