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(Harnessing the adhesive power of ''C. crescentus'' in a standard biological part)
(Harnessing the adhesive power of ''C. crescentus'' in a standard biological part)
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*Nierman, W. et al.  ''Complete genome sequence of <i>Caulobacter crescentus</i>.'' PNAS 98 (7): 4136-4141. (2001)
*Nierman, W. et al.  ''Complete genome sequence of <i>Caulobacter crescentus</i>.'' PNAS 98 (7): 4136-4141. (2001)
The genome of <i>C. crescentus</i> has been completely sequenced; there are 3767 genes composed of approximately 4 Mbp of DNA.  This is useful reference for obtaining the sequences of DNA to be used in the future standard biological part.
The genome of <i>C. crescentus</i> has been completely sequenced; there are 3767 genes composed of approximately 4 Mbp of DNA.  This is useful reference for obtaining the sequences of DNA to be used in the future standard biological part.
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*Li, G., Smith, C., Brun, Y., Tang, J.  ''The Elastic Properties of the Caulobacter crescentus Adhesive Holdfast Are Dependent on Oligomers of N-Acetylglucosamine.'' J. Bacteriology 187(1): 257-65. (2005)
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The holdfast of <i>Caulobacter crescentus</i> is examined closely to explore its various properties, and these properties are used to show that the holdfast's properties are largely dependent on the presence of N-Acetylglucosamine polymers.  For instance, the holdfast stalk's strength is independent of its length - it acts as a rigid rod; also, the holdfast exhibits gel-like behavoir (similar to N-Acetylglucosamine).  When enzymes that can cleave N-Acetylglucosamine were introduced, the strength of the holdfast dropped significantly, supporting the hypothesis that its oligomers are important in maintaining the integrity of the holdfast.

Revision as of 23:17, 3 May 2006

Harnessing the adhesive power of C. crescentus in a standard biological part

We would like to propose further investigation of the adhesive mechanism of C. crescentus, which was recently shown to be the strongest biological adhesive known. Access to an adhesive would be invaluable in many applications of synthetic biology if the functionality could be isolated genetically and its properties quantified ex vivo (outside of its natural host).

  • Tsang et al. Adhesion of single bacterial cells in the micronewton range. PNAS 103 (15): 5764. (2006)

The adhesive properties of C. crescentus are quantified in this paper. Through several experiments it was discovered that the holdfast system in this bacterium has an adhesive strength of 68 N/mm^2, the strongest biological adhesive ever characterized. In fact, in most of their experiments the bacterial stalk broke before the holdfast-substrate bond. It was demonstrated that the presence of GlcNAc polymer was required for the extreme bonding strength, but the mechanism by which GlcNAc functions as an adhesive is unknown.

  • Janakiraman and Brun. Cell Cycle Control of a Holdfast Attachment Gene in Caulobacter crescentus. J. Bacteriology 181 (4): 1118. (1999)

The holdfast is a conglomerate of polysaccharides that is attached to the bacterium by a gene family, named HfaA-D. This gene family is activated during the cell cycle, with the maximum level acheived during the predivisional stage. Additionally, it was discovered that the holdfast is attached to the base of the stem shortly after daughter cells begin stem synthesis.

  • Nierman, W. et al. Complete genome sequence of Caulobacter crescentus. PNAS 98 (7): 4136-4141. (2001)

The genome of C. crescentus has been completely sequenced; there are 3767 genes composed of approximately 4 Mbp of DNA. This is useful reference for obtaining the sequences of DNA to be used in the future standard biological part.

  • Li, G., Smith, C., Brun, Y., Tang, J. The Elastic Properties of the Caulobacter crescentus Adhesive Holdfast Are Dependent on Oligomers of N-Acetylglucosamine. J. Bacteriology 187(1): 257-65. (2005)

The holdfast of Caulobacter crescentus is examined closely to explore its various properties, and these properties are used to show that the holdfast's properties are largely dependent on the presence of N-Acetylglucosamine polymers. For instance, the holdfast stalk's strength is independent of its length - it acts as a rigid rod; also, the holdfast exhibits gel-like behavoir (similar to N-Acetylglucosamine). When enzymes that can cleave N-Acetylglucosamine were introduced, the strength of the holdfast dropped significantly, supporting the hypothesis that its oligomers are important in maintaining the integrity of the holdfast.

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