Our structure 2FBW has the wrong orientation of carboxin heterocycle. In the initial maps the methyl bulge was not apparent, and the bulge due to the extra density of S was misinterpreted as the methyl group. The structure was submitted prematurely and the orientation of carboxin had not been examined critically in the improved density that came with refinement. We probably would have corrected this before release, but for an unusual requirement of "release before acceptance" instead of "hold until publication" from the JBC editor. We were about to leave for a meeting in Bari when this request came (or maybe we were already in the hotel there), so I emailed the annotator to go ahead and release as is. Soon after returning, I realized that we had the orientation of the heterocycle wrong. I've been meaning to correct it ever since but putting it off until I got a second paper with carboxin and five other inhibitors ready, and since we have no funding for complex II and tend to put major effort on projects that may lead to funding, it hasn't happened yet. Anyway, enough excuses, Ruprecht et al. have corrected our structure for us, re-refined 2FBW with the correct orientation, and deposited it as structure 2WYQ, and that would probably be a better starting model. Or we have a further improved model at: http://sb20.lbl.gov/cytbc1/PDB/sqr401coord.pdb I sincerely apologize for any trouble this may have caused.