1ywc: Difference between revisions
No edit summary |
No edit summary |
||
| Line 1: | Line 1: | ||
[[Image:1ywc.gif|left|200px]] | [[Image:1ywc.gif|left|200px]] | ||
'''Structure of the ferrous CO complex of NP4 from Rhodnius Prolixus at pH 7.0''' | {{Structure | ||
|PDB= 1ywc |SIZE=350|CAPTION= <scene name='initialview01'>1ywc</scene>, resolution 1.00Å | |||
|SITE= | |||
|LIGAND= <scene name='pdbligand=HEM:PROTOPORPHYRIN+IX+CONTAINING+FE'>HEM</scene> and <scene name='pdbligand=CMO:CARBON MONOXIDE'>CMO</scene> | |||
|ACTIVITY= | |||
|GENE= | |||
}} | |||
'''Structure of the ferrous CO complex of NP4 from Rhodnius Prolixus at pH 7.0''' | |||
==Overview== | ==Overview== | ||
| Line 7: | Line 16: | ||
==About this Structure== | ==About this Structure== | ||
1YWC is a [ | 1YWC is a [[Single protein]] structure of sequence from [http://en.wikipedia.org/wiki/Rhodnius_prolixus Rhodnius prolixus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1YWC OCA]. | ||
==Reference== | ==Reference== | ||
Ultrahigh resolution structures of nitrophorin 4: heme distortion in ferrous CO and NO complexes., Maes EM, Roberts SA, Weichsel A, Montfort WR, Biochemistry. 2005 Sep 27;44(38):12690-9. PMID:[http:// | Ultrahigh resolution structures of nitrophorin 4: heme distortion in ferrous CO and NO complexes., Maes EM, Roberts SA, Weichsel A, Montfort WR, Biochemistry. 2005 Sep 27;44(38):12690-9. PMID:[http://www.ncbi.nlm.nih.gov/pubmed/16171383 16171383] | ||
[[Category: Rhodnius prolixus]] | [[Category: Rhodnius prolixus]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
| Line 21: | Line 30: | ||
[[Category: ferrous heme; carbon monoxide complex; lipocalin fold; beta barrel]] | [[Category: ferrous heme; carbon monoxide complex; lipocalin fold; beta barrel]] | ||
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Mar 20 15:28:18 2008'' | ||
Revision as of 16:28, 20 March 2008
| |||||||
| , resolution 1.00Å | |||||||
|---|---|---|---|---|---|---|---|
| Ligands: | and | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
Structure of the ferrous CO complex of NP4 from Rhodnius Prolixus at pH 7.0
OverviewOverview
Nitrophorin 4 (NP4), a nitric oxide (NO)-transport protein from the blood-sucking insect Rhodnius prolixus, uses a ferric (Fe3+) heme to deliver NO to its victims. NO binding to NP4 induces a large conformational change and complete desolvation of the distal pocket. The heme is markedly nonplanar, displaying a ruffling distortion postulated to contribute to stabilization of the ferric iron. Here, we report the ferrous (Fe2+) complexes of NP4 with NO, CO, and H2O formed after chemical reduction of the protein and the characterization of these complexes by absorption spectroscopy, flash photolysis, and ultrahigh-resolution crystallography (resolutions vary from 0.9 to 1.08 A). The absorption spectra, both in solution and in the crystal, are typical for six-coordinated ferrous complexes. Closure and desolvation of the distal pocket occurs upon binding CO or NO to the iron regardless of the heme oxidation state, confirming that the conformational change is driven by distal ligand polarity. The degree of heme ruffling is coupled to the nature of the ligand and the iron oxidation state in the following order: (Fe3+)-NO > (Fe2+)-NO > (Fe2+)-CO > (Fe3+)-H2O > (Fe2+)-H2O. The ferrous coordination geometry is as expected, except for the proximal histidine bond, which is shorter than typically found in model compounds. These data are consistent with heme ruffling and coordination geometry serving to stabilize the ferric state of the nitrophorins, a requirement for their physiological function. Possible roles for heme distortion and NO bending in heme protein function are discussed.
About this StructureAbout this Structure
1YWC is a Single protein structure of sequence from Rhodnius prolixus. Full crystallographic information is available from OCA.
ReferenceReference
Ultrahigh resolution structures of nitrophorin 4: heme distortion in ferrous CO and NO complexes., Maes EM, Roberts SA, Weichsel A, Montfort WR, Biochemistry. 2005 Sep 27;44(38):12690-9. PMID:16171383
Page seeded by OCA on Thu Mar 20 15:28:18 2008