From Proteopedia
(Difference between revisions)
proteopedia linkproteopedia link
|
|
| Line 1: |
Line 1: |
| - | [[Image:1x8p.gif|left|200px]] | + | {{Seed}} |
| | + | [[Image:1x8p.png|left|200px]] |
| | | | |
| | <!-- | | <!-- |
| Line 9: |
Line 10: |
| | {{STRUCTURE_1x8p| PDB=1x8p | SCENE= }} | | {{STRUCTURE_1x8p| PDB=1x8p | SCENE= }} |
| | | | |
| - | '''0.85 A Crystal Structure Of Nitrophorin 4 From Rhodnius Prolixus Complexed With Ammonia at pH 7.4'''
| + | ===0.85 A Crystal Structure Of Nitrophorin 4 From Rhodnius Prolixus Complexed With Ammonia at pH 7.4=== |
| | | | |
| | | | |
| - | ==Overview==
| + | <!-- |
| - | The blood-sucking insect Rhodnius prolixus uses nitrophorin 4, a heme protein, to deliver nitric oxide (NO) to a victim, causing vasodilation and improved feeding. Binding of NO occurs at a ferric heme and is modulated by pH. NO binding at lower pH induces a large conformational change involving loops A-B and G-H that leads to distal pocket desolvation and protection of the nitrosyl heme complex. We have determined the crystal structures of Rhodnius nitrophorin 4 to ultrahigh resolution in four functional states: +/-NO at pH = 7.4 and +/-NO at pH = 5.6. The structure with NO at pH 7.4 (1.08 A) is newly determined while the other complexes have been modeled to resolutions much greater than previously reported (1.0-0.85 A). The ultrahigh resolution allowed us to resolve multiple conformers in binding-site loops, leading to a detailed description of the dynamics involved with storing NO in the insect salivary gland at low pH, and releasing NO in response to the increased pH of a victim's tissue. Strikingly, features for both the "open" and "closed" conformers exist under all conditions, suggesting that the flexible loops can transition with relative ease between conformational states. Yet, release of NO from rNP4 is much slower than found for other ferric heme proteins. The structures suggest that highly mobile loops can limit diffusion of diatomic molecules into and out of a protein cavity, a result with implications for the role of protein dynamics in function. | + | The line below this paragraph, {{ABSTRACT_PUBMED_15504026}}, adds the Publication Abstract to the page |
| | + | (as it appears on PubMed at http://www.pubmed.gov), where 15504026 is the PubMed ID number. |
| | + | --> |
| | + | {{ABSTRACT_PUBMED_15504026}} |
| | | | |
| | ==About this Structure== | | ==About this Structure== |
| Line 29: |
Line 33: |
| | [[Category: Ferric heme]] | | [[Category: Ferric heme]] |
| | [[Category: Lipocalin]] | | [[Category: Lipocalin]] |
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sat May 3 14:42:35 2008'' | + | |
| | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Mon Jul 28 00:03:52 2008'' |
Revision as of 21:04, 27 July 2008
Template:STRUCTURE 1x8p
0.85 A Crystal Structure Of Nitrophorin 4 From Rhodnius Prolixus Complexed With Ammonia at pH 7.4
Template:ABSTRACT PUBMED 15504026
About this Structure
1X8P is a Single protein structure of sequence from Rhodnius prolixus. Full crystallographic information is available from OCA.
Reference
Protein functional cycle viewed at atomic resolution: conformational change and mobility in nitrophorin 4 as a function of pH and NO binding., Kondrashov DA, Roberts SA, Weichsel A, Montfort WR, Biochemistry. 2004 Nov 2;43(43):13637-47. PMID:15504026
Page seeded by OCA on Mon Jul 28 00:03:52 2008
