Difference between revisions of "Part:BBa K5246011"
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===Usage and Biology===
 
===Usage and Biology===
 
The HfsK gene from Caulobacter crescentus encodes a 359 amino acid acetyltransferase protein. HfsK is a c-di-GMP effector involved in holdfast biogenesis. Cells lacking HfsK form highly malleable holdfast structures with reduced adhesive strength that cannot support surface colonization. HfsK is a soluble protein that associates with the cell membrane during most of the cell cycle but is transferred to the cytosol in the process of holdfast synthesis. HfsK deacetylates N-acetyl-glucosamine from the holdfast, which results in better adhesive properties.
 
The HfsK gene from Caulobacter crescentus encodes a 359 amino acid acetyltransferase protein. HfsK is a c-di-GMP effector involved in holdfast biogenesis. Cells lacking HfsK form highly malleable holdfast structures with reduced adhesive strength that cannot support surface colonization. HfsK is a soluble protein that associates with the cell membrane during most of the cell cycle but is transferred to the cytosol in the process of holdfast synthesis. HfsK deacetylates N-acetyl-glucosamine from the holdfast, which results in better adhesive properties.
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This part also has a his-tagged variant <a href="https://parts.igem.org/Part:BBa_K5246028">BBa_K5246028</a>.
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===Sequence and Features===
 
===Sequence and Features===

Revision as of 14:21, 28 September 2024


CB2/CB2A HfsK Acetyltransferase

Introduction

Usage and Biology

The HfsK gene from Caulobacter crescentus encodes a 359 amino acid acetyltransferase protein. HfsK is a c-di-GMP effector involved in holdfast biogenesis. Cells lacking HfsK form highly malleable holdfast structures with reduced adhesive strength that cannot support surface colonization. HfsK is a soluble protein that associates with the cell membrane during most of the cell cycle but is transferred to the cytosol in the process of holdfast synthesis. HfsK deacetylates N-acetyl-glucosamine from the holdfast, which results in better adhesive properties.

This part also has a his-tagged variant BBa_K5246028.

Sequence and Features


Assembly Compatibility:
  • 10
    INCOMPATIBLE WITH RFC[10]
    Illegal PstI site found at 64
  • 12
    INCOMPATIBLE WITH RFC[12]
    Illegal PstI site found at 64
  • 21
    INCOMPATIBLE WITH RFC[21]
    Illegal XhoI site found at 793
  • 23
    INCOMPATIBLE WITH RFC[23]
    Illegal PstI site found at 64
  • 25
    INCOMPATIBLE WITH RFC[25]
    Illegal PstI site found at 64
  • 1000
    COMPATIBLE WITH RFC[1000]


Experimental characterization

Bioinformatic analysis

Using CDD analysis, it was identified that HfsK is similar to the GNAT N-acetyltransferase family. Its domains suggest HfsK is part of the Bcls superfamily. Acetyltransferases of this superfamily are usually involved in cellulose biosynthesis. Protein BLAST did not give conclusive results, which could result from a unique HfsK protein amino acid sequence and structure.

DeepTMHMM's protein topology predictions showed that HfsK is most likely a globular protein located on the cytoplasmic side of the membrane.

High confidence scores of AlphaFold 3 structures suggest that HfsK is likely a globular protein. 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).

To summarise, HfsK is most likely a globular N-acetyltransferase. Earlier evidence, combined with our findings, suggests that it plays a role in the deacetylation of N-acetylglucosamine within the holdfast synthesis pathway. [1][2][3]

hfsk.png
Fig. 1. AlphaFold 3 structure showing

References

1. Chepkwony, N.K. and Brun, Y.V. (2021) ‘A polysaccharide deacetylase enhances bacterial adhesion in high-ionic-strength environments’, iScience, 24(9), p. 103071. doi:10.1016/j.isci.2021.103071.
2. Sprecher, K.S. et al. (2017) ‘Cohesive properties of the Caulobacter crescentus holdfast adhesin are regulated by a novel C-di-GMP effector protein’, mBio, 8(2). doi:10.1128/mbio.00294-17.
3. Hershey, D.M., Fiebig, A. and Crosson, S. (2019) ‘A genome-wide analysis of adhesion in Caulobacter crescentus identifies new regulatory and biosynthetic components for holdfast assembly’, mBio, 10(1). doi:10.1128/mbio.02273-18.