1r48
From Proteopedia
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'''Solution structure of the C-terminal cytoplasmic domain residues 468-497 of Escherichia coli protein ProP'''<br /> | '''Solution structure of the C-terminal cytoplasmic domain residues 468-497 of Escherichia coli protein ProP'''<br /> | ||
==Overview== | ==Overview== | ||
| - | Bacteria respond to increasing medium osmolality by accumulating organic | + | Bacteria respond to increasing medium osmolality by accumulating organic solutes that are compatible with cellular functions. Transporter ProP of Escherichia coli, a proton symporter and a member of the major facilitator superfamily, senses osmotic shifts and responds by importing osmolytes such as glycine betaine. ProP contains a cytoplasmic, C-terminal extension that is essential for its activity. A peptide corresponding to the C-terminal extension of ProP forms a homodimeric alpha-helical coiled-coil even though some of its heptad a positions are not occupied by hydrophobic amino acid residues. Unexpectedly, amino acid replacement R488I, occurring at a heptad a position, destabilized the coiled-coil formed by the ProP peptide and attenuated the response of the intact transporter to osmotic upshifts in vivo. Thus, ProP was proposed to dimerize via an antiparallel coiled-coil. We used nuclear magnetic resonance (NMR) spectroscopy to determine the structure of the synthetic peptide corresponding to residues 468-497 of ProP. This region did form an antiparallel coil-coil in which critical residue R488 specifies the antiparallel coiled-coil orientation by forming stabilizing salt-bridges. Charged residues (both acidic and basic) are clustered on the c/g surface of the coiled-coil whereas polar residues are distributed on the b/e surface. This causes the structure to be bent, in contrast to other known antiparallel coiled-coils (those from the hepatitis delta antigen (PDB ID code 1A92) and the bovine F(1) ATPase inhibitor protein (PDB ID code 1HF9)). The coiled-coil and its possible importance for osmosensing are discussed. |
==About this Structure== | ==About this Structure== | ||
| - | 1R48 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/ ]. Full crystallographic information is available from [http:// | + | 1R48 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/ ]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1R48 OCA]. |
==Reference== | ==Reference== | ||
Solution structure of the C-terminal antiparallel coiled-coil domain from Escherichia coli osmosensor ProP., Zoetewey DL, Tripet BP, Kutateladze TG, Overduin MJ, Wood JM, Hodges RS, J Mol Biol. 2003 Dec 12;334(5):1063-76. PMID:[http://ispc.weizmann.ac.il//pmbin/getpm?pmid=14643666 14643666] | Solution structure of the C-terminal antiparallel coiled-coil domain from Escherichia coli osmosensor ProP., Zoetewey DL, Tripet BP, Kutateladze TG, Overduin MJ, Wood JM, Hodges RS, J Mol Biol. 2003 Dec 12;334(5):1063-76. PMID:[http://ispc.weizmann.ac.il//pmbin/getpm?pmid=14643666 14643666] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
| - | [[Category: Hodges, R | + | [[Category: Hodges, R S.]] |
| - | [[Category: Kutateladze, T | + | [[Category: Kutateladze, T G.]] |
| - | [[Category: Overduin, M | + | [[Category: Overduin, M J.]] |
| - | [[Category: Tripet, B | + | [[Category: Tripet, B P.]] |
| - | [[Category: Wood, J | + | [[Category: Wood, J M.]] |
| - | [[Category: Zoetewey, D | + | [[Category: Zoetewey, D L.]] |
[[Category: antiparallel]] | [[Category: antiparallel]] | ||
[[Category: coiled-coil]] | [[Category: coiled-coil]] | ||
| Line 24: | Line 24: | ||
[[Category: two-stranded homodimer]] | [[Category: two-stranded homodimer]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 14:46:54 2008'' |
Revision as of 12:46, 21 February 2008
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Solution structure of the C-terminal cytoplasmic domain residues 468-497 of Escherichia coli protein ProP
Overview
Bacteria respond to increasing medium osmolality by accumulating organic solutes that are compatible with cellular functions. Transporter ProP of Escherichia coli, a proton symporter and a member of the major facilitator superfamily, senses osmotic shifts and responds by importing osmolytes such as glycine betaine. ProP contains a cytoplasmic, C-terminal extension that is essential for its activity. A peptide corresponding to the C-terminal extension of ProP forms a homodimeric alpha-helical coiled-coil even though some of its heptad a positions are not occupied by hydrophobic amino acid residues. Unexpectedly, amino acid replacement R488I, occurring at a heptad a position, destabilized the coiled-coil formed by the ProP peptide and attenuated the response of the intact transporter to osmotic upshifts in vivo. Thus, ProP was proposed to dimerize via an antiparallel coiled-coil. We used nuclear magnetic resonance (NMR) spectroscopy to determine the structure of the synthetic peptide corresponding to residues 468-497 of ProP. This region did form an antiparallel coil-coil in which critical residue R488 specifies the antiparallel coiled-coil orientation by forming stabilizing salt-bridges. Charged residues (both acidic and basic) are clustered on the c/g surface of the coiled-coil whereas polar residues are distributed on the b/e surface. This causes the structure to be bent, in contrast to other known antiparallel coiled-coils (those from the hepatitis delta antigen (PDB ID code 1A92) and the bovine F(1) ATPase inhibitor protein (PDB ID code 1HF9)). The coiled-coil and its possible importance for osmosensing are discussed.
About this Structure
1R48 is a Single protein structure of sequence from [1]. Full crystallographic information is available from OCA.
Reference
Solution structure of the C-terminal antiparallel coiled-coil domain from Escherichia coli osmosensor ProP., Zoetewey DL, Tripet BP, Kutateladze TG, Overduin MJ, Wood JM, Hodges RS, J Mol Biol. 2003 Dec 12;334(5):1063-76. PMID:14643666
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