Crystal structure of O-methyltransferase CalO6 from the calicheamicin biosynthetic pathway: a case of challenging structure determination at low resolution.

ABSTRACT:

Background

Calicheamicins (CAL) are enedyine natural products with potent antibiotic and cytotoxic activity, used in anticancer therapy. The O-methyltransferase CalO6 is proposed to catalyze methylation of the hydroxyl moiety at the C2 position of the orsellinic acid group of CAL.

Results

Crystals of CalO6 diffracted non-isotropically, with the usable data extending to 3.4 Å. While no single method of crystal structure determination yielded a structure of CalO6, we were able to determine its structure by using molecular replacement-guided single wavelength anomalous dispersion by using diffraction data from native crystals of CalO6 and a highly non-isomorphous mercury derivative. The structure of CalO6 reveals the methyltransferase fold and dimeric organization characteristi

SUBMITTER: Tsodikov OV 

PROVIDER: S-EPMC4501126 | biostudies-literature | 2015 Jul

REPOSITORIES: biostudies-literature