6XCR

NMR structure of Ost4 in DPC micelles


Experimental Data Snapshot

  • Method: SOLUTION NMR
  • Conformers Calculated: 100 
  • Conformers Submitted: 20 
  • Selection Criteria: structures with the lowest energy 

wwPDB Validation   3D Report Full Report


This is version 1.1 of the entry. See complete history


Literature

NMR and MD simulations reveal the impact of the V23D mutation on the function of yeast oligosaccharyltransferase subunit Ost4.

Chaudhary, B.P.Zoetewey, D.L.McCullagh, M.J.Mohanty, S.

(2021) Glycobiology 31: 838-850

  • DOI: 10.1093/glycob/cwab002
  • Primary Citation of Related Structures:  
    6XCR, 6XCU

  • PubMed Abstract: 
  • Asparagine-linked glycosylation, also known as N-linked glycosylation, is an essential and highly conserved co- and post-translational protein modification in eukaryotes and some prokaryotes. In the central step of this reaction, a carbohydrate moiety is transferred from a lipid-linked donor to the side-chain of a consensus asparagine in a nascent protein as it is synthesized at the ribosome ...

    Asparagine-linked glycosylation, also known as N-linked glycosylation, is an essential and highly conserved co- and post-translational protein modification in eukaryotes and some prokaryotes. In the central step of this reaction, a carbohydrate moiety is transferred from a lipid-linked donor to the side-chain of a consensus asparagine in a nascent protein as it is synthesized at the ribosome. Complete loss of oligosaccharyltransferase (OST) function is lethal in eukaryotes. This reaction is carried out by a membrane-associated multisubunit enzyme, OST, localized in the endoplasmic reticulum. The smallest subunit, Ost4, contains a single membrane-spanning helix that is critical for maintaining the stability and activity of OST. Mutation of any residue from Met18 to Ile24 of Ost4 destabilizes the enzyme complex, affecting its activity. Here, we report solution nuclear magnetic resonance structures and molecular dynamics (MD) simulations of Ost4 and Ost4V23D in micelles. Our studies revealed that while the point mutation did not impact the structure of the protein, it affected its position and solvent exposure in the membrane mimetic environment. Furthermore, our MD simulations of the membrane-bound OST complex containing either WT or V23D mutant demonstrated disruption of most hydrophobic helix-helix interactions between Ost4V23D and transmembrane TM12 and TM13 of Stt3. This disengagement of Ost4V23D from the OST complex led to solvent exposure of the D23 residue in the hydrophobic pocket created by these interactions. Our study not only solves the structures of yeast Ost4 subunit and its mutant but also provides a basis for the destabilization of the OST complex and reduced OST activity.


    Organizational Affiliation

    Department of Chemistry, Oklahoma State University, Stillwater, OK 74078, USA.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
OligosaccharyltransferaseA45Saccharomyces cerevisiae YJM789Mutation(s): 0 
Gene Names: OST4SCY_0690
EC: 2.4.1.119
Membrane Entity: Yes 
UniProt
Find proteins for Q99380 (Saccharomyces cerevisiae (strain ATCC 204508 / S288c))
Explore Q99380 
Go to UniProtKB:  Q99380
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ99380
Protein Feature View
Expand
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: SOLUTION NMR
  • Conformers Calculated: 100 
  • Conformers Submitted: 20 
  • Selection Criteria: structures with the lowest energy 

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2021-02-10
    Type: Initial release
  • Version 1.1: 2021-09-29
    Changes: Database references