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| [[Image:2jub.jpg|left|200px]] | | {{Seed}} |
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| {{STRUCTURE_2jub| PDB=2jub | SCENE= }} | | {{STRUCTURE_2jub| PDB=2jub | SCENE= }} |
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| '''Solution structure of IPI*'''
| | ===Solution structure of IPI*=== |
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| ==Overview==
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| 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.
| | The line below this paragraph, {{ABSTRACT_PUBMED_18037438}}, adds the Publication Abstract to the page |
| | (as it appears on PubMed at http://www.pubmed.gov), where 18037438 is the PubMed ID number. |
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| | {{ABSTRACT_PUBMED_18037438}} |
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| ==About this Structure== | | ==About this Structure== |
| 2JUB is a [[Single protein]] structure of sequence from [http://en.wikipedia.org/wiki/Enterobacteria_phage_t4 Enterobacteria phage t4]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2JUB OCA]. | | 2JUB is a [[Single protein]] structure of sequence from [http://en.wikipedia.org/wiki/Enterobacteria_phage_t4 Enterobacteria phage t4]. Full experimental information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2JUB OCA]. |
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| ==Reference== | | ==Reference== |
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| [[Category: Solution]] | | [[Category: Solution]] |
| [[Category: T4 phage]] | | [[Category: T4 phage]] |
| ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sun May 4 09:17:55 2008'' | | |
| | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Tue Jul 29 08:19:38 2008'' |