Crystal structure of a distal site double mutant of sperm whale myoglobin at 1.6 A resolution.
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.
Rizzi
M
M
Dipartimento di Genetica e Microbiologia, Università di Pavia, Italy.
Bolognesi
M
M
Coda
A
A
Cutruzzolà
F
F
Allocatelli
C T
CT
Brancaccio
A
A
Brunori
M
M
D000818:Animals; D001665:Binding Sites; D009154:Mutation; D009211:Myoglobin / Q000737:chemistry* / Q000235:genetics; D011487:Protein Conformation; D014907:Whales; D014961:X-Ray Diffraction
D009211:Myoglobin