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2jub
From Proteopedia
(New page: 200px<br /><applet load="2jub" size="350" color="white" frame="true" align="right" spinBox="true" caption="2jub" /> '''Solution structure of IPI*'''<br /> ==Overv...) |
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==Overview== | ==Overview== | ||
| - | Phage T4 protects its DNA from the two-gene-encoded gmrS/gmrD | + | Phage T4 protects its DNA from the two-gene-encoded gmrS/gmrD (glucose-modified hydroxymethylcytosine restriction endonuclease) CT of pathogenic Escherichia coli, CT596, by injecting several hundred copies of the 76-amino-acid-residue nuclease inhibitor, IPI*, into the infected host. Here, the three-dimensional solution structure of mature IPI* is reported as determined by nuclear magnetic resonance techniques using 1290 experimental nuclear Overhauser effect and dipolar coupling constraints ( approximately 17 constraints per residue). Close examination of this oblate-shaped protein structure reveals a novel fold consisting of two small beta-sheets (beta1: B1 and B2; beta2: B3-B5) flanked at the N- and C-termini by alpha-helices (H1 and H2). Such a fold is very compact in shape and allows ejection of IPI* through the narrow 30-A portal and tail tube apertures of the virion without unfolding. Structural and dynamic measurements identify an exposed hydrophobic knob that is a putative gmrS/gmrD-binding site. A single gene from the uropathogenic E. coli UT189, which codes for a gmrS/gmrD-like UT fusion enzyme (with approximately 90% identity to the heterodimeric CT enzyme), has evolved IPI* inhibitor immunity. Analysis of the gmrS/gmrD restriction endonuclease enzyme family and its IPI* family phage antagonists reveals an evolutionary pathway that has elaborated a surprisingly diverse and specifically fitted set of coevolving attack and defense structures. |
==About this Structure== | ==About this Structure== | ||
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==Reference== | ==Reference== | ||
| - | Restriction | + | Restriction endonuclease inhibitor IPI* of bacteriophage T4: a novel structure for a dedicated target., Rifat D, Wright NT, Varney KM, Weber DJ, Black LW, J Mol Biol. 2008 Jan 18;375(3):720-34. Epub 2007 Nov 1. PMID:[http://ispc.weizmann.ac.il//pmbin/getpm?pmid=18037438 18037438] |
[[Category: Enterobacteria phage tw28]] | [[Category: Enterobacteria phage tw28]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
| - | [[Category: Black, L | + | [[Category: Black, L W.]] |
[[Category: Rifat, D.]] | [[Category: Rifat, D.]] | ||
| - | [[Category: Varney, K | + | [[Category: Varney, K M.]] |
| - | [[Category: Weber, D | + | [[Category: Weber, D J.]] |
| - | [[Category: Wright, N | + | [[Category: Wright, N T.]] |
[[Category: endonuclease inhibitor]] | [[Category: endonuclease inhibitor]] | ||
[[Category: ipi*]] | [[Category: ipi*]] | ||
| Line 23: | Line 23: | ||
[[Category: t4 phage]] | [[Category: t4 phage]] | ||
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 18:05:55 2008'' |
Revision as of 16:05, 21 February 2008
|
Solution structure of IPI*
Overview
Phage T4 protects its DNA from the two-gene-encoded gmrS/gmrD (glucose-modified hydroxymethylcytosine restriction endonuclease) CT of pathogenic Escherichia coli, CT596, by injecting several hundred copies of the 76-amino-acid-residue nuclease inhibitor, IPI*, into the infected host. Here, the three-dimensional solution structure of mature IPI* is reported as determined by nuclear magnetic resonance techniques using 1290 experimental nuclear Overhauser effect and dipolar coupling constraints ( approximately 17 constraints per residue). Close examination of this oblate-shaped protein structure reveals a novel fold consisting of two small beta-sheets (beta1: B1 and B2; beta2: B3-B5) flanked at the N- and C-termini by alpha-helices (H1 and H2). Such a fold is very compact in shape and allows ejection of IPI* through the narrow 30-A portal and tail tube apertures of the virion without unfolding. Structural and dynamic measurements identify an exposed hydrophobic knob that is a putative gmrS/gmrD-binding site. A single gene from the uropathogenic E. coli UT189, which codes for a gmrS/gmrD-like UT fusion enzyme (with approximately 90% identity to the heterodimeric CT enzyme), has evolved IPI* inhibitor immunity. Analysis of the gmrS/gmrD restriction endonuclease enzyme family and its IPI* family phage antagonists reveals an evolutionary pathway that has elaborated a surprisingly diverse and specifically fitted set of coevolving attack and defense structures.
About this Structure
2JUB is a Single protein structure of sequence from Enterobacteria phage tw28. Full crystallographic information is available from OCA.
Reference
Restriction endonuclease inhibitor IPI* of bacteriophage T4: a novel structure for a dedicated target., Rifat D, Wright NT, Varney KM, Weber DJ, Black LW, J Mol Biol. 2008 Jan 18;375(3):720-34. Epub 2007 Nov 1. PMID:18037438
Page seeded by OCA on Thu Feb 21 18:05:55 2008
