1vb5
From Proteopedia
(New page: 200px<br /><applet load="1vb5" size="450" color="white" frame="true" align="right" spinBox="true" caption="1vb5, resolution 2.2Å" /> '''Crystal Structure Ana...) |
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| - | [[Image:1vb5.jpg|left|200px]]<br /><applet load="1vb5" size=" | + | [[Image:1vb5.jpg|left|200px]]<br /><applet load="1vb5" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1vb5, resolution 2.2Å" /> | caption="1vb5, resolution 2.2Å" /> | ||
'''Crystal Structure Analysis of the Pyrococcus horikoshii OT3 translation initiation factor eIF-2B'''<br /> | '''Crystal Structure Analysis of the Pyrococcus horikoshii OT3 translation initiation factor eIF-2B'''<br /> | ||
==Overview== | ==Overview== | ||
| - | Eukaryotic translation initiation factor 2B (eIF2B) is the | + | Eukaryotic translation initiation factor 2B (eIF2B) is the guanine-nucleotide exchange factor for eukaryotic initiation factor 2 (eIF2). eIF2B is a heteropentameric protein composed of alpha- subunits. The alpha, beta, and delta subunits form a regulatory subcomplex, while the gamma and form a catalytic subcomplex. Archaea possess homologues of alpha, beta, and delta subunits of eIF2B. Here, we report the three-dimensional structure of an archaeal regulatory subunit (aIF2Balpha) from the hyperthermophilic archaeon Pyrococcus horikoshii OT3 determined by X-ray crystallography at 2.2A resolution. aIF2Balpha consists of two subdomains, an N-domain (residues 1-95) and a C-domain (residues 96-276), connected by a long alpha-helix (alpha5: 78-106). The N-domain contains a five helix bundle structure, while the C-domain folds into the alpha/beta structure, thus showing similarity to D-ribose-5-phosphate isomerase structure. The presence of two molecules in the crystallographic asymmetric unit and the gel filtration analysis suggest a dimeric structure of aIF2Balpha in solution, interacting with each other by C-domains. Furthermore, the crystallographic 3-fold symmetry generates a homohexameric structure of aIF2Balpha; the interaction is primarily mediated by the long alpha-helix at the N-domains. This structure suggests an architecture of the three subunits, alpha, beta, and delta, in the regulatory subcomplex within eIF2B. |
==About this Structure== | ==About this Structure== | ||
| - | 1VB5 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Pyrococcus_horikoshii Pyrococcus horikoshii]. Full crystallographic information is available from [http:// | + | 1VB5 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Pyrococcus_horikoshii Pyrococcus horikoshii]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1VB5 OCA]. |
==Reference== | ==Reference== | ||
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[[Category: initiation factor]] | [[Category: initiation factor]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 15:33:22 2008'' |
Revision as of 13:33, 21 February 2008
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Crystal Structure Analysis of the Pyrococcus horikoshii OT3 translation initiation factor eIF-2B
Overview
Eukaryotic translation initiation factor 2B (eIF2B) is the guanine-nucleotide exchange factor for eukaryotic initiation factor 2 (eIF2). eIF2B is a heteropentameric protein composed of alpha- subunits. The alpha, beta, and delta subunits form a regulatory subcomplex, while the gamma and form a catalytic subcomplex. Archaea possess homologues of alpha, beta, and delta subunits of eIF2B. Here, we report the three-dimensional structure of an archaeal regulatory subunit (aIF2Balpha) from the hyperthermophilic archaeon Pyrococcus horikoshii OT3 determined by X-ray crystallography at 2.2A resolution. aIF2Balpha consists of two subdomains, an N-domain (residues 1-95) and a C-domain (residues 96-276), connected by a long alpha-helix (alpha5: 78-106). The N-domain contains a five helix bundle structure, while the C-domain folds into the alpha/beta structure, thus showing similarity to D-ribose-5-phosphate isomerase structure. The presence of two molecules in the crystallographic asymmetric unit and the gel filtration analysis suggest a dimeric structure of aIF2Balpha in solution, interacting with each other by C-domains. Furthermore, the crystallographic 3-fold symmetry generates a homohexameric structure of aIF2Balpha; the interaction is primarily mediated by the long alpha-helix at the N-domains. This structure suggests an architecture of the three subunits, alpha, beta, and delta, in the regulatory subcomplex within eIF2B.
About this Structure
1VB5 is a Single protein structure of sequence from Pyrococcus horikoshii. Full crystallographic information is available from OCA.
Reference
Crystal structure of the regulatory subunit of archaeal initiation factor 2B (aIF2B) from hyperthermophilic archaeon Pyrococcus horikoshii OT3: a proposed structure of the regulatory subcomplex of eukaryotic IF2B., Kakuta Y, Tahara M, Maetani S, Yao M, Tanaka I, Kimura M, Biochem Biophys Res Commun. 2004 Jul 2;319(3):725-32. PMID:15184043
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