Primary Citation of Related Structures:   1FCS
PubMed Abstract: 
The three-dimensional structure of sperm whale myoglobin His64(E7)-->Val,Thr67(E10)-->Arg double mutant has been studied by X-ray crystallography at 1.6 A resolution, and refined to a crystallographic R-factor of 0.197. The Arg67(E10) side chain is extended in the direction of the ligand binding site, and its NH1 atom is at a distance of 3 ...
The three-dimensional structure of sperm whale myoglobin His64(E7)-->Val,Thr67(E10)-->Arg double mutant has been studied by X-ray crystallography at 1.6 A resolution, and refined to a crystallographic R-factor of 0.197. The Arg67(E10) side chain is extended in the direction of the ligand binding site, and its NH1 atom is at a distance of 3.11 A from the NH1 atom of Arg45(CD3), which is also pointing towards the distal site. Both are kept in this position by hydrogen bonding and electrostatic interactions with a solvent sulfate ion, located amongst the two, on the protein surface. No liganded water molecule is present at the sixth coordination position of the Fe(III) heme.
Related Citations: 
Control and Recognition of Anionic Ligands in Myoglobin Cutruzzola, F., Allocatelli, C.T., Ascenzi, P., Bolognesi, M., Sligar, S.G., Brunori, M. (1991) FEBS Lett 282: 281
Binding Mode of Azide to Ferric Aplysia Limacina Myoglobin. Crystallographic Analysis at 1.9 Angstroms Resolution Mattevi, A., Gatti, G., Coda, A., Rizzi, M., Ascenzi, P., Brunori, M., Bolognesi, M. (1991) J Mol Recognit 4: 1
Organizational Affiliation: 
Dipartimento di Genetica e Microbiologia, Università di Pavia, Italy.