Outward facing structure of apo CST

Experimental Data Snapshot

  • Resolution: 3.40 Å
  • R-Value Free: 0.286 
  • R-Value Work: 0.268 
  • R-Value Observed: 0.269 

wwPDB Validation   3D Report Full Report

This is version 1.2 of the entry. See complete history


Structural basis for the delivery of activated sialic acid into Golgi for sialyation.

Nji, E.Gulati, A.Qureshi, A.A.Coincon, M.Drew, D.

(2019) Nat Struct Mol Biol 26: 415-423

  • DOI: https://doi.org/10.1038/s41594-019-0225-y
  • Primary Citation of Related Structures:  
    6I1R, 6I1Z

  • PubMed Abstract: 

    The decoration of secretory glycoproteins and glycolipids with sialic acid is critical to many physiological and pathological processes. Sialyation is dependent on a continuous supply of sialic acid into Golgi organelles in the form of CMP-sialic acid. Translocation of CMP-sialic acid into Golgi is carried out by the CMP-sialic acid transporter (CST). Mutations in human CST are linked to glycosylation disorders, and CST is important for glycopathway engineering, as it is critical for sialyation efficiency of therapeutic glycoproteins. The mechanism of how CMP-sialic acid is recognized and translocated across Golgi membranes in exchange for CMP is poorly understood. Here we have determined the crystal structure of a Zea mays CST in complex with CMP. We conclude that the specificity of CST for CMP-sialic acid is established by the recognition of the nucleotide CMP to such an extent that they are mechanistically capable of both passive and coupled antiporter activity.

  • Organizational Affiliation

    Department of Biochemistry and Biophysics, Stockholm University, Stockholm, Sweden.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
CMP-sialic acid transporter 1
A, B
322Zea maysMutation(s): 5 
Gene Names: 100274139ZEAMMB73_Zm00001d046060
Membrane Entity: Yes 
Find proteins for B4FZ94 (Zea mays)
Explore B4FZ94 
Go to UniProtKB:  B4FZ94
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupB4FZ94
Sequence Annotations
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Resolution: 3.40 Å
  • R-Value Free: 0.286 
  • R-Value Work: 0.268 
  • R-Value Observed: 0.269 
  • Space Group: P 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 51.58α = 82.83
b = 69.46β = 83.43
c = 102.03γ = 68.22
Software Package:
Software NamePurpose
Aimlessdata scaling
PDB_EXTRACTdata extraction
XDSdata reduction

Structure Validation

View Full Validation Report

Entry History & Funding Information

Deposition Data

Funding OrganizationLocationGrant Number
Knut and Alice Wallenberg FoundationSweden--

Revision History  (Full details and data files)

  • Version 1.0: 2019-06-05
    Type: Initial release
  • Version 1.1: 2019-06-19
    Changes: Data collection, Database references
  • Version 1.2: 2024-01-24
    Changes: Data collection, Database references, Refinement description