THE STRUCTURE OF RUBREDOXIN FROM DESULFOVIBRIO-DESULFURICANS STRAIN-27774 AT 1.5-A RESOLUTION

The structure of a small rubredoxin from the bacterium Desulfovibrio desulfuricans has been determined and refined at 1.5 angstrom 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 angstrom 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.