2w7z

Publication Abstract from PubMed

The pentapeptide-repeat protein EfsQnr from Enterococcus faecalis protects DNA gyrase from inhibition by fluoroquinolones. EfsQnr was cloned and purified to homogeneity, but failed to produce diffraction-quality crystals in initial crystallization screens. Treatment of EfsQnr with glutaraldehyde and the strong reducing agent borane-dimethylamine resulted in a derivatized protein which produced crystals that diffracted to 1.6 A resolution; their structure was subsequently determined by single-wavelength anomalous dispersion. Analysis of the derivatized protein using Fourier transform ion cyclotron resonance mass spectrometry indicated a mass increase of 68 Da per free amino group. Electron-density maps about a limited number of structurally ordered lysines indicated that the modification was a cyclic pentylation of free amines, producing piperidine groups.

Crystallization of a pentapeptide-repeat protein by reductive cyclic pentylation of free amines with glutaraldehyde.,Vetting MW, Hegde SS, Blanchard JS Acta Crystallogr D Biol Crystallogr. 2009 May;65(Pt 5):462-9. Epub 2009, Apr 18. PMID:19390151^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.