6I7S

Microsomal triglyceride transfer protein


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.5 Å
  • R-Value Free: 0.257 
  • R-Value Work: 0.204 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history

Literature

The crystal structure of human microsomal triglyceride transfer protein.

Biterova, E.I.Isupov, M.N.Keegan, R.M.Lebedev, A.A.Sohail, A.A.Liaqat, I.Alanen, H.I.Ruddock, L.W.

(2019) Proc.Natl.Acad.Sci.USA 116: 17251-17260

  • DOI: 10.1073/pnas.1903029116

  • PubMed Abstract: 
  • Microsomal triglyceride transfer protein (MTP) plays an essential role in lipid metabolism, especially in the biogenesis of very low-density lipoproteins and chylomicrons via the transfer of neutral lipids and the assembly of apoB-containing lipoprot ...

    Microsomal triglyceride transfer protein (MTP) plays an essential role in lipid metabolism, especially in the biogenesis of very low-density lipoproteins and chylomicrons via the transfer of neutral lipids and the assembly of apoB-containing lipoproteins. Our understanding of the molecular mechanisms of MTP has been hindered by a lack of structural information of this heterodimeric complex comprising an MTPα subunit and a protein disulfide isomerase (PDI) β-subunit. The structure of MTP presented here gives important insights into the potential mechanisms of action of this essential lipid transfer molecule, structure-based rationale for previously reported disease-causing mutations, and a means for rational drug design against cardiovascular disease and obesity. In contrast to the previously reported structure of lipovitellin, which has a funnel-like lipid-binding cavity, the lipid-binding site is encompassed in a β-sandwich formed by 2 β-sheets from the C-terminal domain of MTPα. The lipid-binding cavity of MTPα is large enough to accommodate a single lipid. PDI independently has a major role in oxidative protein folding in the endoplasmic reticulum. Comparison of the mechanism of MTPα binding by PDI with previously published structures gives insights into large protein substrate binding by PDI and suggests that the previous structures of human PDI represent the "substrate-bound" and "free" states rather than differences arising from redox state.


    Organizational Affiliation

    Faculty of Biochemistry and Molecular Medicine, University of Oulu, 90220 Oulu, Finland; lloyd.ruddock@oulu.fi.,Biocenter Oulu, University of Oulu, 90014 Oulu, Finland.,Henry Wellcome Biocatalysis Centre, Biosciences, University of Exeter, EX4 4QD Exeter, United Kingdom.,Faculty of Biochemistry and Molecular Medicine, University of Oulu, 90220 Oulu, Finland.,Research Complex at Harwell, Science and Technology Facilities Council Rutherford Appleton Laboratory, Didcot OX11 0FA, United Kingdom.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Protein disulfide-isomerase
A, B
492Homo sapiensMutation(s): 0 
Gene Names: P4HB (ERBA2L, PDI, PDIA1, PO4DB)
EC: 5.3.4.1
Find proteins for P07237 (Homo sapiens)
Go to Gene View: P4HB
Go to UniProtKB:  P07237
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetails
Microsomal triglyceride transfer protein large subunit
G, H
884Homo sapiensMutation(s): 0 
Gene Names: MTTP (MTP)
Find proteins for P55157 (Homo sapiens)
Go to Gene View: MTTP
Go to UniProtKB:  P55157
Small Molecules
Ligands 8 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
PE4
Query on PE4

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H
2-{2-[2-(2-{2-[2-(2-ETHOXY-ETHOXY)-ETHOXY]-ETHOXY}-ETHOXY)-ETHOXY]-ETHOXY}-ETHANOL
POLYETHYLENE GLYCOL PEG4000
C16 H34 O8
PJWQOENWHPEPKI-UHFFFAOYSA-N
 Ligand Interaction
SO4
Query on SO4

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B, G, H
SULFATE ION
O4 S
QAOWNCQODCNURD-UHFFFAOYSA-L
 Ligand Interaction
PE5
Query on PE5

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G, H
3,6,9,12,15,18,21,24-OCTAOXAHEXACOSAN-1-OL
2-(2-{2-[2-(2-{2-[2-(2-ETHOXY-ETHOXY)-ETHOXY]-ETHOXY}-ETHOXY)-ETHOXY]-ETHOXY}-ETHOXY)-ETHANOL, POLYETHYLENE GLYCOL PEG400
C18 H38 O9
CUDPPTPIUWYGFI-UHFFFAOYSA-N
 Ligand Interaction
CA
Query on CA

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A, B
CALCIUM ION
Ca
BHPQYMZQTOCNFJ-UHFFFAOYSA-N
 Ligand Interaction
EDO
Query on EDO

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A, B, G, H
1,2-ETHANEDIOL
ETHYLENE GLYCOL
C2 H6 O2
LYCAIKOWRPUZTN-UHFFFAOYSA-N
 Ligand Interaction
PGE
Query on PGE

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B, G, H
TRIETHYLENE GLYCOL
C6 H14 O4
ZIBGPFATKBEMQZ-UHFFFAOYSA-N
 Ligand Interaction
PEG
Query on PEG

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B, G, H
DI(HYDROXYETHYL)ETHER
C4 H10 O3
MTHSVFCYNBDYFN-UHFFFAOYSA-N
 Ligand Interaction
TRS
Query on TRS

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G
2-AMINO-2-HYDROXYMETHYL-PROPANE-1,3-DIOL
TRIS BUFFER
C4 H12 N O3
LENZDBCJOHFCAS-UHFFFAOYSA-O
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.5 Å
  • R-Value Free: 0.257 
  • R-Value Work: 0.204 
  • Space Group: P 1
Unit Cell:
Length (Å)Angle (°)
a = 77.537α = 89.81
b = 105.595β = 76.95
c = 112.269γ = 74.24
Software Package:
Software NamePurpose
XSCALEdata scaling
XDSdata reduction
PDB_EXTRACTdata extraction
PHASERphasing
REFMACrefinement

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History & Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
Academy of FinlandFinland266457
Academy of FinlandFinland272573

Revision History 

  • Version 1.0: 2019-08-21
    Type: Initial release
  • Version 1.1: 2019-09-04
    Type: Data collection, Database references