Solution structure of an octanoyl- loaded acyl carrier protein domain from module MLSA2 of the mycolactone polyketide synthase.

Experimental Data Snapshot

  • Method: SOLUTION NMR
  • Conformers Calculated: 50 
  • Conformers Submitted: 20 
  • Selection Criteria: structures with the least restraint violations 

wwPDB Validation   3D Report Full Report

This is version 1.5 of the entry. See complete history


Sticky swinging arm dynamics: studies of an acyl carrier protein domain from the mycolactone polyketide synthase.

Vance, S.Tkachenko, O.Thomas, B.Bassuni, M.Hong, H.Nietlispach, D.Broadhurst, W.

(2016) Biochem J 473: 1097-1110

  • DOI: https://doi.org/10.1042/BCJ20160041
  • Primary Citation of Related Structures:  
    5HV8, 5HVC

  • PubMed Abstract: 

    Type I modular polyketide synthases (PKSs) produce polyketide natural products by passing a growing acyl substrate chain between a series of enzyme domains housed within a gigantic multifunctional polypeptide assembly. Throughout each round of chain extension and modification reactions, the substrate stays covalently linked to an acyl carrier protein (ACP) domain. In the present study we report on the solution structure and dynamics of an ACP domain excised from MLSA2, module 9 of the PKS system that constructs the macrolactone ring of the toxin mycolactone, cause of the tropical disease Buruli ulcer. After modification of apo ACP with 4'-phosphopantetheine (Ppant) to create the holo form, (15)N nuclear spin relaxation and paramagnetic relaxation enhancement (PRE) experiments suggest that the prosthetic group swings freely. The minimal chemical shift perturbations displayed by Ppant-attached C3 and C4 acyl chains imply that these substrate-mimics remain exposed to solvent at the end of a flexible Ppant arm. By contrast, hexanoyl and octanoyl chains yield much larger chemical shift perturbations, indicating that they interact with the surface of the domain. The solution structure of octanoyl-ACP shows the Ppant arm bending to allow the acyl chain to nestle into a nonpolar pocket, whereas the prosthetic group itself remains largely solvent exposed. Although the highly reduced octanoyl group is not a natural substrate for the ACP from MLSA2, similar presentation modes would permit partner enzyme domains to recognize an acyl group while it is bound to the surface of its carrier protein, allowing simultaneous interactions with both the substrate and the ACP.

  • Organizational Affiliation

    Department of Biochemistry, University of Cambridge, 80 Tennis Court Road, Cambridge CB2 1GA, U.K. Crescendo Biologics Ltd, Meditrina Building 260, Babraham Research Campus, Cambridge CB22 3AT, U.K.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Type I modular polyketide synthase95Mycobacterium ulceransMutation(s): 0 
Gene Names: mlsA2MUP039c
Find proteins for Q6MZA5 (Mycobacterium ulcerans (strain Agy99))
Explore Q6MZA5 
Go to UniProtKB:  Q6MZA5
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ6MZA5
Sequence Annotations
  • Reference Sequence
Small Molecules
Ligands 1 Unique
IDChains Name / Formula / InChI Key2D Diagram3D Interactions
Query on 66S

Download Ideal Coordinates CCD File 
B [auth A]S-[2-({N-[(2R)-2-hydroxy-3,3-dimethyl-4-(phosphonooxy)butanoyl]-beta-alanyl}amino)ethyl] octanethioate
C19 H37 N2 O8 P S
Experimental Data & Validation

Experimental Data

  • Method: SOLUTION NMR
  • Conformers Calculated: 50 
  • Conformers Submitted: 20 
  • Selection Criteria: structures with the least restraint violations 

Structure Validation

View Full Validation Report

Entry History & Funding Information

Deposition Data

Funding OrganizationLocationGrant Number
Wellcome TrustUnited Kingdom094252/Z/10/Z

Revision History  (Full details and data files)

  • Version 1.0: 2016-03-09
    Type: Initial release
  • Version 1.1: 2016-03-30
    Changes: Database references
  • Version 1.2: 2016-04-20
    Changes: Database references
  • Version 1.3: 2018-01-17
    Changes: Structure summary
  • Version 1.4: 2019-05-08
    Changes: Data collection
  • Version 1.5: 2019-10-23
    Changes: Data collection, Experimental preparation