Difference between revisions of "Part:BBa K4275003"

Revision as of 09:55, 12 October 2022

TaLPMO-t

Fusing the dockerin, lytic polysaccharide monooxygenase (TaLPMO-t) is able to bind to the scaffoldin —cellulosome integrating protein A(CipA)— by type 1 dockerin-cohesin interaction, which enables enzyme proximity synergy and enzyme-substrate–microbe complex synergy. Therefore, the enzyme activity is boosted and further accelerates the polysaccharide degradation efficiency with assistance from the electron donor Cellobiose dehydrogenase (CDH).

As a cellulase booster, LPMO is a monocopper enzyme that can open the three-dimensional network formed by polysaccharides like cellulose and chitin by hydrolysing the polymer into oligomers. Therefore, this enzyme enables other hydrolyases to approach their substrate, boosting their hydrolysis efficiency as a result.

Figure 1 The 3D structure of the protein predicted by Alphafold2.

Usage and Biology

LPMO belongs to the class of monocopper enzymes and its activity was originally discovered to be involved in the enzymatic degradation of chitin. Receiving an electron from Cellobiose dehydrogenase CDH or other electron donors like ascorbic acid, substrate binding is likely preceded by the reduction of the ground-state LPMO–Cu(II) to LPMO–Cu(I). Then, LPMOs conduct hydroxylation to cleave the glycosidic bonds, introducing chain breaks in the crystalline regions of densely packed cellulose fibrils and thereby providing new ends for processive hydrolases and promoting loosening of the cellulose structure. Then, LPMOs are oxidised by the hydrogen peroxide or oxygen back to their inactivate state LPMO–Cu(II), ready for the next binding.

Sequence and Features

References

1. Harris, Paul V. et al. "Stimulation Of Lignocellulosic Biomass Hydrolysis By Proteins Of Glycoside Hydrolase Family 61: Structure And Function Of A Large, Enigmatic Family". Biochemistry, vol 49, no. 15, 2010, pp. 3305-3316. American Chemical Society (ACS), https://doi.org/10.1021/bi100009p.