Part:BBa_K5246007

CB2/CB2A HfsG Glycosyltransferase

Usage and Biology

HfsG gene encodes a cytoplasmic protein of 309 aa homologous to family 2 glycosyltransferases. Transferrs sugar units from UDP-GlcNAc to oligosaccharide, catalyzes the polymerization of GlcNAc. C.Crescentus HfsG mutants were completely devoid of holdfast material

Sequence and Features

Assembly Compatibility:

• 10
  COMPATIBLE WITH RFC[10]
• 12
  INCOMPATIBLE WITH RFC[12]

  Illegal NotI site found at 825
  
• 21
  INCOMPATIBLE WITH RFC[21]

  Illegal XhoI site found at 28
  
• 23
  COMPATIBLE WITH RFC[23]
• 25
  INCOMPATIBLE WITH RFC[25]

  Illegal NgoMIV site found at 480
  
• 1000
  COMPATIBLE WITH RFC[1000]

Experimental characterization

Bioinformatic analysis

CDD and protein BLAST analysis suggest that HfsG is a glucosyltransferase family 2 protein. Proteins of this family are involved in cell wall biosynthesis. HfsG is similar to the WecA protein in E.Coli that catalyzes the transfer of the GlcNAc-1-phosphate moiety from UDP-GlcNAc onto the carrier lipid undecaprenyl phosphate. In the case of HfsG, it catalyzes the transfer of UDP-GlcNAc to the sugar acceptor made earlier in the holdfast synthesis pathway.

Protein topology analysis using DeepTMHMM suggests that HfsG is a globular protein located in the cytoplasm. AlphaFold 3 structures further confirm it. A pTM score above 0.5 suggests that the predicted overall structure may closely resemble the true protein fold, while ipTM indicates the accuracy of the subunit positioning within the complex. Values higher than 0.8 represent confident, high-quality predictions (Fig. 1).

HfsG is family 2 glycosyltransferase similar to WecA of E.Coli. This globular protein transfers UDP-GlcNAc to the acceptor molecule, our conclusions are in agreement with existing research. [1][2][3]

Fig. 1. AlphaFold 3 structure showing

References

1. Toh, E., Kurtz, Harry D. and Brun, Y.V. (2008) ‘Characterization of the Caulobacter crescentus holdfast polysaccharide biosynthesis pathway reveals significant redundancy in the initiating glycosyltransferase and polymerase steps’, Journal of Bacteriology, 190(21), pp. 7219–7231. doi:10.1128/jb.01003-08.
2. Hardy, G.G. et al. (2018) ‘Mutations in sugar-nucleotide synthesis genes restore holdfast polysaccharide anchoring to Caulobacter crescentus holdfast anchor mutants’, Journal of Bacteriology, 200(3). doi:10.1128/jb.00597-17.
3. Sulkowski, N.I. et al. (2019) ‘A multiprotein complex anchors adhesive holdfast at the outer membrane of Caulobacter crescentus’, Journal of Bacteriology, 201(18). doi:10.1128/jb.00112-19.