1rkl
From Proteopedia
(New page: 200px<br /><applet load="1rkl" size="450" color="white" frame="true" align="right" spinBox="true" caption="1rkl" /> '''NMR structure of yeast oligosaccharyltransfe...) |
|||
| Line 1: | Line 1: | ||
| - | [[Image:1rkl.gif|left|200px]]<br /><applet load="1rkl" size=" | + | [[Image:1rkl.gif|left|200px]]<br /><applet load="1rkl" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1rkl" /> | caption="1rkl" /> | ||
'''NMR structure of yeast oligosaccharyltransferase subunit Ost4p'''<br /> | '''NMR structure of yeast oligosaccharyltransferase subunit Ost4p'''<br /> | ||
==Overview== | ==Overview== | ||
| - | N-glycosylation of proteins is an essential, highly conserved modification | + | N-glycosylation of proteins is an essential, highly conserved modification reaction that occurs in all eukaryotes and some prokaryotes. This process is catalyzed by oligosaccharyltransferase (OT), a multisubunit enzyme localized in the endoplasmic reticulum. Complete loss of N-glycosylation is lethal in all organisms. In Saccharomyces cerevisiae, OT is composed of nine nonidentical membrane proteins. Here, we report the atomic structure of an OT subunit from S. cerevisiae, Ost4p. This unusually small membrane protein containing only 36 residues folds into a well formed, kinked helix in the model-membrane solvent system used in this study. The residues critical for the OT activity and the stability of Stt3p-Ost4p-Ost3p subcomplex are located in helix alpha2, the larger cytosolic half of this kinked helix. The residues known to disrupt Ost4p-Stt3p complex form a well defined ridge in the 3D structure. Taking together prior mutational studies and the NMR structure of Ost4p, we propose that in the OT complex Stt3p is packed against the alpha 2-helix of Ost4p by using a "ridges-into-grooves" model, with Met-18, Leu-21, and Ile-24 as the packing interface on one face, whereas Ost3p is involved in interactions with Met-19, Thr-20, Ile-22, and Val-23 on the other face. |
==About this Structure== | ==About this Structure== | ||
| - | 1RKL is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/ ]. Active as [http://en.wikipedia.org/wiki/Dolichyl-diphosphooligosaccharide--protein_glycotransferase Dolichyl-diphosphooligosaccharide--protein glycotransferase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.4.1.119 2.4.1.119] Full crystallographic information is available from [http:// | + | 1RKL is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/ ]. Active as [http://en.wikipedia.org/wiki/Dolichyl-diphosphooligosaccharide--protein_glycotransferase Dolichyl-diphosphooligosaccharide--protein glycotransferase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.4.1.119 2.4.1.119] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1RKL OCA]. |
==Reference== | ==Reference== | ||
| Line 13: | Line 13: | ||
[[Category: Dolichyl-diphosphooligosaccharide--protein glycotransferase]] | [[Category: Dolichyl-diphosphooligosaccharide--protein glycotransferase]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
| - | [[Category: Lennarz, W | + | [[Category: Lennarz, W J.]] |
[[Category: Mohanty, S.]] | [[Category: Mohanty, S.]] | ||
[[Category: Zubkov, S.]] | [[Category: Zubkov, S.]] | ||
[[Category: membrane protein]] | [[Category: membrane protein]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 14:51:54 2008'' |
Revision as of 12:52, 21 February 2008
|
NMR structure of yeast oligosaccharyltransferase subunit Ost4p
Overview
N-glycosylation of proteins is an essential, highly conserved modification reaction that occurs in all eukaryotes and some prokaryotes. This process is catalyzed by oligosaccharyltransferase (OT), a multisubunit enzyme localized in the endoplasmic reticulum. Complete loss of N-glycosylation is lethal in all organisms. In Saccharomyces cerevisiae, OT is composed of nine nonidentical membrane proteins. Here, we report the atomic structure of an OT subunit from S. cerevisiae, Ost4p. This unusually small membrane protein containing only 36 residues folds into a well formed, kinked helix in the model-membrane solvent system used in this study. The residues critical for the OT activity and the stability of Stt3p-Ost4p-Ost3p subcomplex are located in helix alpha2, the larger cytosolic half of this kinked helix. The residues known to disrupt Ost4p-Stt3p complex form a well defined ridge in the 3D structure. Taking together prior mutational studies and the NMR structure of Ost4p, we propose that in the OT complex Stt3p is packed against the alpha 2-helix of Ost4p by using a "ridges-into-grooves" model, with Met-18, Leu-21, and Ile-24 as the packing interface on one face, whereas Ost3p is involved in interactions with Met-19, Thr-20, Ile-22, and Val-23 on the other face.
About this Structure
1RKL is a Single protein structure of sequence from [1]. Active as Dolichyl-diphosphooligosaccharide--protein glycotransferase, with EC number 2.4.1.119 Full crystallographic information is available from OCA.
Reference
Structural basis for the function of a minimembrane protein subunit of yeast oligosaccharyltransferase., Zubkov S, Lennarz WJ, Mohanty S, Proc Natl Acad Sci U S A. 2004 Mar 16;101(11):3821-6. Epub 2004 Mar 4. PMID:15001703
Page seeded by OCA on Thu Feb 21 14:51:54 2008
