Part:BBa_K5246020

HB HfsH Deacetylase

Usage and Biology

The polysaccharide deacetylase HfsH is required for H. baltica adhesion. Holdfast polysaccharides in H. baltica HfsH mutants lack cohesive and adhesive properties. Research instigating the Hirschia baltica genome found that hfsH is in the hfs locus while hfsK and its paralogs are outside the hfs locus. Color coding corresponds to homologs and paralogs. Hash marks indicate genes found in a different location in the genome. [1] HfsH expression correlates positively with holdfast binding in high ionic strength. HfsH is an important factor for adherence in high ionic-strength environments, adhesion and biofilm formation. It is also crucial for the retention of holdfast thiols and galactose monosaccharides. [1]

Sequence and Features

Assembly Compatibility:

• 10
  COMPATIBLE WITH RFC[10]
• 12
  COMPATIBLE WITH RFC[12]
• 21
  COMPATIBLE WITH RFC[21]
• 23
  COMPATIBLE WITH RFC[23]
• 25
  INCOMPATIBLE WITH RFC[25]

  Illegal NgoMIV site found at 385
  
• 1000
  COMPATIBLE WITH RFC[1000]

This part also has a non his-tagged variant BBa_K5246031.

Experimental characterization

Bioinformatic analysis

Conserved domain database analysis suggests that HfsH is part of the carbohydrate esterase 4 superfamily and polysaccharide deacetylase family. Proteins of this family may catalyze the N- or O- deacetylation of a substrate. Protein BLAST results show high similarity to peptidoglycan N-acetylglucosamine deacetylase and other polysaccharide deacetylases.

Topology analysis with DeepTMHMM and AlphaFold3 structure showed that HfsH is most probably a globular protein located in the cytoplasm. 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.

HfsH is a globular polysaccharide deacetylase that catalyses the deacetylation of N-acetylglucosamine in the holdfast synthesis pathway, previous research supports our conclusions. [1][2][3]

References

1. Wan, Z. et al. (2013a) ‘The adhesive and cohesive properties of a bacterial polysaccharide adhesin are modulated by a deacetylase’, Molecular Microbiology, 88(3), pp. 486–500. doi:10.1111/mmi.12199.
2. 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.
3. Liu, Q. et al. (2022) ‘The screening and expression of polysaccharide deacetylase from caulobacter crescentus and its function analysis’, Biotechnology and Applied Biochemistry, 70(2), pp. 688–696. doi:10.1002/bab.2390.