Methylmannose polysaccharide mannosyltransferase from M. hassiacum

Experimental Data Snapshot

  • Resolution: 2.75 Å
  • R-Value Free: 0.287 
  • R-Value Work: 0.269 
  • R-Value Observed: 0.270 

wwPDB Validation   3D Report Full Report

This is version 1.2 of the entry. See complete history


Self-recycling and partially conservative replication of mycobacterial methylmannose polysaccharides.

Maranha, A.Costa, M.Ripoll-Rozada, J.Manso, J.A.Miranda, V.Mendes, V.M.Manadas, B.Macedo-Ribeiro, S.Ventura, M.R.Pereira, P.J.B.Empadinhas, N.

(2023) Commun Biol 6: 108-108

  • DOI: https://doi.org/10.1038/s42003-023-04448-3
  • Primary Citation of Related Structures:  
    7QSG, 7QSJ

  • PubMed Abstract: 

    The steep increase in nontuberculous mycobacteria (NTM) infections makes understanding their unique physiology an urgent health priority. NTM synthesize two polysaccharides proposed to modulate fatty acid metabolism: the ubiquitous 6-O-methylglucose lipopolysaccharide, and the 3-O-methylmannose polysaccharide (MMP) so far detected in rapidly growing mycobacteria. The recent identification of a unique MMP methyltransferase implicated the adjacent genes in MMP biosynthesis. We report a wide distribution of this gene cluster in NTM, including slowly growing mycobacteria such as Mycobacterium avium, which we reveal to produce MMP. Using a combination of MMP purification and chemoenzymatic syntheses of intermediates, we identified the biosynthetic mechanism of MMP, relying on two enzymes that we characterized biochemically and structurally: a previously undescribed α-endomannosidase that hydrolyses MMP into defined-sized mannoligosaccharides that prime the elongation of new daughter MMP chains by a rare α-(1→4)-mannosyltransferase. Therefore, MMP biogenesis occurs through a partially conservative replication mechanism, whose disruption affected mycobacterial growth rate at low temperature.

  • Organizational Affiliation

    CNC - Center for Neuroscience and Cell Biology, University of Coimbra, 3004-504, Coimbra, Portugal.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
D-inositol 3-phosphate glycosyltransferase
A, B
437Mycolicibacterium hassiacumMutation(s): 0 
Gene Names: mshA_2C731_4166MHAS_04402
Find proteins for K5BE02 (Mycolicibacterium hassiacum (strain DSM 44199 / CIP 105218 / JCM 12690 / 3849))
Explore K5BE02 
Go to UniProtKB:  K5BE02
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupK5BE02
Sequence Annotations
  • Reference Sequence
Experimental Data & Validation

Experimental Data

Unit Cell:
Length ( Å )Angle ( ˚ )
a = 136.261α = 90
b = 77.4β = 106.49
c = 101.21γ = 90
Software Package:
Software NamePurpose
iMOSFLMdata reduction
Aimlessdata scaling
Cootmodel building

Structure Validation

View Full Validation Report

Entry History & Funding Information

Deposition Data

Funding OrganizationLocationGrant Number
Fundacao para a Ciencia e a TecnologiaPortugalPTDC/BTM-TEC/29221/2017

Revision History  (Full details and data files)

  • Version 1.0: 2023-01-25
    Type: Initial release
  • Version 1.1: 2023-02-08
    Changes: Database references
  • Version 1.2: 2024-02-07
    Changes: Data collection, Refinement description