1y4e
From Proteopedia
(New page: 200px<br /> <applet load="1y4e" size="450" color="white" frame="true" align="right" spinBox="true" caption="1y4e" /> '''NMR structure of transmembrane segment IV o...) |
|||
| Line 1: | Line 1: | ||
| - | [[Image:1y4e.gif|left|200px]]<br /> | + | [[Image:1y4e.gif|left|200px]]<br /><applet load="1y4e" size="350" color="white" frame="true" align="right" spinBox="true" |
| - | <applet load="1y4e" size=" | + | |
caption="1y4e" /> | caption="1y4e" /> | ||
'''NMR structure of transmembrane segment IV of the NHE1 isoform of the Na+/H+ exchanger'''<br /> | '''NMR structure of transmembrane segment IV of the NHE1 isoform of the Na+/H+ exchanger'''<br /> | ||
==Overview== | ==Overview== | ||
| - | The Na(+)/H(+) exchanger isoform 1 is a ubiquitously expressed integral | + | The Na(+)/H(+) exchanger isoform 1 is a ubiquitously expressed integral membrane protein that regulates intracellular pH in mammals. We characterized the structural and functional aspects of the critical transmembrane (TM) segment IV. Each residue was mutated to cysteine in cysteine-less NHE1. TM IV was exquisitely sensitive to mutation with 10 of 23 mutations causing greatly reduced expression and/or activity. The Phe(161) --> Cys mutant was inhibited by treatment with the water-soluble sulfhydryl-reactive compounds [2-(trimethylammonium)ethyl]methanethiosulfonate and [2-sulfonatoethyl]methanethiosulfonate, suggesting it is a pore-lining residue. The structure of purified TM IV peptide was determined using high resolution NMR in a CD(3)OH:CDCl(3):H(2)O mixture and in Me(2)SO. In CD(3)OH: CDCl(3):H(2)O, TM IV was structured but not as a canonical alpha-helix. Residues Asp(159)-Leu(162) were a series of beta-turns; residues Leu(165)-Pro(168) showed an extended structure, and residues Ile(169)-Phe(176) were helical in character. These three structured regions rotated quite freely with respect to the others. In Me(2)SO, the structure was much less defined. Our results demonstrate that TM IV is an unusually structured transmembrane segment that is exquisitely sensitive to mutagenesis and that Phe(161) is a pore-lining residue. |
==About this Structure== | ==About this Structure== | ||
| - | 1Y4E is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens]. Full crystallographic information is available from [http:// | + | 1Y4E is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1Y4E OCA]. |
==Reference== | ==Reference== | ||
| Line 16: | Line 15: | ||
[[Category: Fliegel, L.]] | [[Category: Fliegel, L.]] | ||
[[Category: Li, X.]] | [[Category: Li, X.]] | ||
| - | [[Category: Lindhout, D | + | [[Category: Lindhout, D A.]] |
[[Category: Liu, Y.]] | [[Category: Liu, Y.]] | ||
| - | [[Category: Rainey, J | + | [[Category: Rainey, J K.]] |
| - | [[Category: Slepkov, E | + | [[Category: Slepkov, E R.]] |
| - | [[Category: Sykes, B | + | [[Category: Sykes, B D.]] |
[[Category: nhe1 isoform]] | [[Category: nhe1 isoform]] | ||
[[Category: transmembrane]] | [[Category: transmembrane]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 16:01:39 2008'' |
Revision as of 14:01, 21 February 2008
|
NMR structure of transmembrane segment IV of the NHE1 isoform of the Na+/H+ exchanger
Overview
The Na(+)/H(+) exchanger isoform 1 is a ubiquitously expressed integral membrane protein that regulates intracellular pH in mammals. We characterized the structural and functional aspects of the critical transmembrane (TM) segment IV. Each residue was mutated to cysteine in cysteine-less NHE1. TM IV was exquisitely sensitive to mutation with 10 of 23 mutations causing greatly reduced expression and/or activity. The Phe(161) --> Cys mutant was inhibited by treatment with the water-soluble sulfhydryl-reactive compounds [2-(trimethylammonium)ethyl]methanethiosulfonate and [2-sulfonatoethyl]methanethiosulfonate, suggesting it is a pore-lining residue. The structure of purified TM IV peptide was determined using high resolution NMR in a CD(3)OH:CDCl(3):H(2)O mixture and in Me(2)SO. In CD(3)OH: CDCl(3):H(2)O, TM IV was structured but not as a canonical alpha-helix. Residues Asp(159)-Leu(162) were a series of beta-turns; residues Leu(165)-Pro(168) showed an extended structure, and residues Ile(169)-Phe(176) were helical in character. These three structured regions rotated quite freely with respect to the others. In Me(2)SO, the structure was much less defined. Our results demonstrate that TM IV is an unusually structured transmembrane segment that is exquisitely sensitive to mutagenesis and that Phe(161) is a pore-lining residue.
About this Structure
1Y4E is a Single protein structure of sequence from Homo sapiens. Full crystallographic information is available from OCA.
Reference
Structural and functional characterization of transmembrane segment IV of the NHE1 isoform of the Na+/H+ exchanger., Slepkov ER, Rainey JK, Li X, Liu Y, Cheng FJ, Lindhout DA, Sykes BD, Fliegel L, J Biol Chem. 2005 May 6;280(18):17863-72. Epub 2005 Jan 26. PMID:15677483
Page seeded by OCA on Thu Feb 21 16:01:39 2008
