1dp8
From Proteopedia
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CRYSTAL STRUCTURE OF THE NITRIC OXIDE BOUND FIXL HEME DOMAIN
Overview
The FixL heme domain serves as the dioxygen switch in the FixL/FixJ, two-component system of Rhizobia. Recent structural studies of the, Bradyrhizobium japonicum FixL heme domain (BjFixLH) have suggested an, allosteric mechanism that is distinct from the classical hemoglobin model., To gain further insight into the FixL sensing mechanism, structures of, BjFixLH bound to dioxygen, imidazole, and nitric oxide have been, determined. These structures, particularly the structure of BjFixLH bound, to its physiological ligand, dioxygen, have helped to address a number of, important issues relevant to the BjFixLH sensing mechanism. On the basis, of the oxy-BjFixLH structure, a conserved arginine is found to stabilize, the dioxygen ligand in a mode reminiscent of the distal histidine in, classical myoglobins and hemoglobins. The structure of BjFixLH bound to, imidazole elucidates the structural requirements for accommodating, sterically bulky ligands. Finally, the structure of BjFixLH bound to, nitric oxide provides evidence for a structural intermediate in the, heme-driven conformational change.
About this Structure
1DP8 is a Single protein structure of sequence from Bradyrhizobium japonicum with NO and HEM as ligands. Full crystallographic information is available from OCA.
Reference
New mechanistic insights from structural studies of the oxygen-sensing domain of Bradyrhizobium japonicum FixL., Gong W, Hao B, Chan MK, Biochemistry. 2000 Apr 11;39(14):3955-62. PMID:10747783
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