hey Mischa I would guess that is a split cobalt/metal site occupancy 0.1 and 0.9 or something like that. If you calculate an anomalous difference map you may be able to confirm/reject that suggestion, depending on the strength of the anomalous signal.
cheers Preben On 07.07.2011, at 17:07, Machius, Mischa Christian wrote: > Y'all, > > I was wondering if anyone had any thoughts about a feature we observe with a > metal-binding site: we have a cobalt that is bound by four histidines and one > carboxyl group. There is extra density near the cobalt. See pictures below. > The extra density spans the NE2 atoms from two histidines. The Fo-Fc peak > (green) has a height of up to 10 sigma (eight molecules in the asymmetric > unit, all showing the same feature). > > I placed a water molecule into the density to get some distances: the > distances between the peak and the neighboring histidine NE2 atoms is ~1.8Å > and ~2.0Å, resp. The distance between the peak and the cobalt is ~1.7Å. The > resolution is 1.24Å. > > Any input would be greatly appreciated. > > Many thanks in advance! > > Cheers! > MM > > > <Screen shot 2011-07-07 at 9.44.43 AM.png><ATT00001.c><Screen shot 2011-07-07 > at 9.44.55 AM.png> J. Preben Morth, Ph.D Group Leader Membrane Transport Group Nordic EMBL Partnership Centre for Molecular Medicine Norway (NCMM) University of Oslo P.O.Box 1137 Blindern 0318 Oslo, Norway Email: [email protected] Tel: +47 2284 0794 http://www.jpmorth.dk
