9PQZ | pdb_00009pqz

Structure of MPT domain of S. cerevisiae type-I FAS, thio-esterified to palmitate

• PDB DOI: https://doi.org/10.2210/pdb9PQZ/pdb
• EM Map EMD-71794: EMDB EMDataResource

• Classification: BIOSYNTHETIC PROTEIN
• Organism(s): Saccharomyces cerevisiae
• Expression System: Saccharomyces cerevisiae
• Mutation(s): No 


• Deposited: 2025-07-23 Released: 2025-12-10 
• Deposition Author(s): Samani, E.K., Mazhab-Jafari, M.T.
• Funding Organization(s): Canadian Institutes of Health Research (CIHR), Natural Sciences and Engineering Research Council (NSERC, Canada)

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Experimental Data Snapshot

• Method: ELECTRON MICROSCOPY
• Resolution: 2.22 Å
• Aggregation State: PARTICLE 
• Reconstruction Method: SINGLE PARTICLE 

Starting Model: experimental

Literature

Structural basis of product recognition by Mycobacterium tuberculosis fatty acid synthase.

Samani, E.K., Hasan, S.M.N., Keszei, A.F.A., Heydari, M., Mazhab-Jafari, M.T.

(2026) Protein Sci 35: e70412-e70412

• PubMed: 41427673 
• DOI: https://doi.org/10.1002/pro.70412
• Primary Citation of Related Structures:  
  9PQX, 9PQY, 9PQZ


• PubMed Abstract: 
  

  Microbial iterative fatty acid synthases (FAS) are versatile multienzymes under scrutiny for their potential as anti-infectious targets and their biotechnological applications. They produce saturated fatty acids with defined chain length and release them as coenzyme A-conjugates. How they recognize appropriate acyl length to initiate the process of product release is unknown. Here, we resolved two intermediate state structures of FAS, one from each of the two organisms: bacterium Mycobacterium tuberculosis and yeast Saccharomyces cerevisiae. These structures reveal how acyl carrier protein (ACP) domain and nascent fatty acids interact with the substrate-promiscuous malonyl-palmitoyl transferase (MPT) domain that is involved in product cleavage from the enzyme. MPT adopts a transient channel necessary for the accommodation of long-chain fatty acids. This channel is formed by the transient retraction of a conserved arginine side chain involved in malonate binding. These insights uncover structural determinants that enable M. tuberculosis type I FAS to produce very long-chain fatty acids used for evading host immunity in tuberculosis (TB).

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Organizational Affiliation: 
• Department of Medical Biophysics, University of Toronto, Toronto, Ontario, Canada.
Princess Margaret Cancer Center, University Health Network, Toronto, Ontario, Canada.

Biological Assembly 1  

Global Symmetry: Asymmetric - C1 
Global Stoichiometry: Hetero 2-mer - A1B1 

Biological assembly 1 assigned by authors.

Biological Assembly Evidence: electron microscopy

Macromolecule Content 

• Total Structure Weight: 436.36 kDa 
• Atom Count: 3,773 
• Modeled Residue Count: 475 
• Deposited Residue Count: 3,938 
• Unique protein chains: 2

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
Fatty acid synthase subunit alpha	A	1,887	Saccharomyces cerevisiae	Mutation(s): 0  Gene Names: FAS2, YPL231W, P1409 EC: 2.3.1.86 (PDB Primary Data), 1.1.1.100 (PDB Primary Data), 2.3.1.41 (PDB Primary Data)
UniProt
Find proteins for P19097 (Saccharomyces cerevisiae (strain ATCC 204508 / S288c)) Explore P19097  Go to UniProtKB:  P19097

Entity ID: 2
Molecule	Chains	Sequence Length	Organism	Details	Image
Fatty acid synthase subunit beta	B [auth G]	2,051	Saccharomyces cerevisiae	Mutation(s): 0  Gene Names: FAS1, YKL182W EC: 2.3.1.86 (PDB Primary Data), 4.2.1.59 (PDB Primary Data), 1.3.1.9 (PDB Primary Data), 2.3.1.38 (PDB Primary Data), 2.3.1.39 (PDB Primary Data), 3.1.2.14 (PDB Primary Data)
UniProt
Find proteins for P07149 (Saccharomyces cerevisiae (strain ATCC 204508 / S288c)) Explore P07149  Go to UniProtKB:  P07149

Experimental Data & Validation

Experimental Data

• Method: ELECTRON MICROSCOPY
• Resolution: 2.22 Å
• Aggregation State: PARTICLE 
• Reconstruction Method: SINGLE PARTICLE 

EM Software:

Task	Software Package	Version
RECONSTRUCTION	cryoSPARC
MODEL REFINEMENT	PHENIX

Structure Validation

Entry History & Funding Information

Deposition Data

• Released Date: 2025-12-10 
Deposition Author(s): Samani, E.K., Mazhab-Jafari, M.T.

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Funding Organization	Location	Grant Number
Canadian Institutes of Health Research (CIHR)	Canada	195698
Canadian Institutes of Health Research (CIHR)	Canada	419240
Natural Sciences and Engineering Research Council (NSERC, Canada)	Canada	RGPIN-2018-06070

Revision History  

• Version 1.0: 2025-12-10
  Type: Initial release
  
• Version 1.1: 2026-01-14
  Changes: Data collection, Database references