5ut8 | pdb_00005ut8

Deoxy form of sperm whale myoglobin H64A

spinqualitylabelsall models 5ut8, resolution 1.78Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 5ut8 is a 1 chain structure with sequence from Physeter catodon. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 1.78Å Ligands: GOL, HEM, SO4 Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function MYG_PHYMC Serves as a reserve supply of oxygen and facilitates the movement of oxygen within muscles. Publication Abstract from PubMed The globular dioxygen binding heme protein myoglobin (Mb) is present in several species. Its interactions with the simple nitrogen oxides, namely, nitric oxide (NO) and nitrite, have been known for decades, but the physiological relevance has only recently become more fully appreciated. We previously reported the O-nitrito mode of binding of nitrite to ferric horse heart wild-type (wt) Mb(III) and human hemoglobin. We have expanded on this work and report the interactions of nitrite with wt sperm whale (sw) Mb(III) and its H64A, H64Q, and V68A/I107Y mutants whose dissociation constants increase in the following order: H64Q < wt < V68A/I107Y < H64A. We also report their X-ray crystal structures that reveal the O-nitrito mode of binding of nitrite to these derivatives. The Mb(II)-mediated reductions of nitrite to NO and structural data for the wt and mutant Mb(II)-NOs are described. We show that their FeNO orientations vary with distal pocket identity, with the FeNO moieties pointing toward the hydrophobic interiors when the His64 residue is present but toward the hydrophilic exterior when this His64 residue is absent in this set of mutants. This correlates with the nature of H-bonding to the bound NO ligand (nitrosyl O vs N atom). Quantum mechanics and hybrid quantum mechanics and molecular mechanics calculations help elucidate the origin of the experimentally preferred NO orientations. In a few cases, the calculations reproduce the experimentally observed orientations only when the whole protein is taken into consideration. Nitrosyl Myoglobins and Their Nitrite Precursors: Crystal Structural and Quantum Mechanics and Molecular Mechanics Theoretical Investigations of Preferred Fe -NO Ligand Orientations in Myoglobin Distal Pockets.,Wang B, Shi Y, Tejero J, Powell SM, Thomas LM, Gladwin MT, Shiva S, Zhang Y, Richter-Addo GB Biochemistry. 2018 Aug 14;57(32):4788-4802. doi: 10.1021/acs.biochem.8b00542., Epub 2018 Jul 27. PMID:29999305 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Myoglobin 3D structures

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