Abstact

The structure of a small rubredoxin from the bacterium Desulfovibrio desulfuricans has been determined and refined at 1.5 A resolution. The hairpin loop containing seven residues in other rubredoxins is missing in this 45 residue molecule, and once that fact was determined by amino acid sequencing studies, refinement progressed smoothly to an R value of 0.093 for all reflections from 5 to 1.5 A resolution. Nearly all of the water molecules in the well-ordered triclinic unit cell have been added to the crystallographic model. As in the other refined rubredoxin models, the Fe-S4 complex is slightly distorted from ideal tetrahedral coordination.