Thioester protein crosslinks: Difference between revisions

Revision as of 22:56, 28 June 2021

Thioester bonds between cysteine and glutamine sidechains can form covalent cross-links between polypeptide chains.

Thioester bonds are one way that ubiquitin may be attached to proteins (ubiquitinylation; see also Ubiquitin and Ubiquitination).

Thioester bonds in complement proteins C3 and C4 are involved in tagging pathogens for destruction by the immune system, via the alternate complement activation pathway.

Thioester bonds occur in thioester domains (TED) of Gram-positive bacteria, where they are thought to mediate covalent adhesion of bacteria to host cells^[1]^[2]. Many surface proteins of Gram-positive bacteria are predicted to contain TED as well as isopeptide and ester cross-links. This family of proteins is termed TIE proteins for thioester, isopeptide, ester proteins^[2]. Examples: 2xi9, 6fwy.
- In a dramatic example, the pilus tip adhesin of Streptococcus pyogenes forms dimers in the presence of spermidine, a di-amine that forms thiopeptide bonds with the Gln211 residues in two adhesin protein chains, illustrated in 4c0z^[3].

In addition to the thioester bonds discussed above, other covalent cross-links between polypeptide chains include:

↑ Nakata M, Kreikemeyer B. Genetics, Structure, and Function of Group A Streptococcal Pili. Front Microbiol. 2021 Feb 9;12:616508. doi: 10.3389/fmicb.2021.616508., eCollection 2021. PMID:33633705 doi:http://dx.doi.org/10.3389/fmicb.2021.616508
↑ ^2.0 ^2.1 Miller OK, Banfield MJ, Schwarz-Linek U. A new structural class of bacterial thioester domains reveals a slipknot topology. Protein Sci. 2018 Jul 27. doi: 10.1002/pro.3478. PMID:30052296 doi:http://dx.doi.org/10.1002/pro.3478
↑ Linke-Winnebeck C, Paterson NG, Young PG, Middleditch MJ, Greenwood DR, Witte G, Baker EN. Structural model for the covalent adhesion of the Streptococcus pyogenes pilus through a thioester bond. J Biol Chem. 2013 Nov 12. PMID:24220033 doi:http://dx.doi.org/10.1074/jbc.M113.523761

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 *Thioester bonds occur in thioester domains (TED) of Gram-positive bacteria, where they are thought to mediate covalent adhesion of bacteria to host cells<ref name="nakata2021">PMID:33633705</ref><ref name="slipknot">PMID: 30052296</ref>. Many surface proteins of Gram-positive bacteria are predicted to contain TED as well as [[isopeptide bond|isopeptide]] and ester cross-links. This family of proteins is termed <b>TIE proteins</b> for thioester, isopeptide, ester proteins<ref name="slipknot" />. Examples: [[2xi9]], [[6fwy]].
-**In a dramatic example, the pilus tip adhesin of ''Streptococcus pyogenes'' forms dimers in the presence of spermidine, a di-amine that forms thiopeptide bonds with the Gln211 residues in two adhesin protein chains<ref name="linke-winnebeck2014">PMID: 24220033</ref>.
+**In a dramatic example, the pilus tip adhesin of ''Streptococcus pyogenes'' forms dimers in the presence of spermidine, a di-amine that forms thiopeptide bonds with the Gln211 residues in two adhesin protein chains, illustrated in [[4c0z]]<ref name="linke-winnebeck2014">PMID: 24220033</ref>.
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