Coding

Part:BBa_K137067

Designed by: Doug Tischer   Group: iGEM08_Caltech   (2008-07-31)


katG

This is one of the two catalases from E. coli.

Information contributed by City of London UK (2021)

Part information is collated here to help future users of the BioBrick registry.

Metadata:

  • Group: City of London UK 2021
  • Author: Lucas Ng
  • Summary: Added information collated from existing scientific studies

katG is a bifunctional enzyme, displaying both catalase activity and broad-spectrum peroxidase activity. Additionally, it has roles as a NADH oxidase, INH lyase and isonicotinoyl-NAD synthase. [1]

It's cofactor is heme B (iron-protoporphyrin IX), of which it binds two groups per tetramer [2].

Following biosynthesis, the N-terminus is blocked. Furthermore, the three residue Trp-Tyr-Met cross-link forms, which is important for its activity as a catalase[2].

Catalase reaction

KatG catalase.png

[3]

The optimum pH is 7.5 [1] [2]:

pH KM (mM) Vmax (µmol/min/mg enzyme)
5.5-6.0 35 3730
7.0 4.2 2220
7.5 3.9

Peroxidase reaction

KatG peroxidase.png

[4]

The optimum pH is 4.25 [1] [2]:

  • With H2O2, KM = 60 µM
  • With ABTS, KM = 24 µM and Vmax = 18 µmol/min/mg enzyme

References

  1. ↑ 1.0 1.1 1.2 Singh, Rahul, Ben Wiseman, Taweewat Deemagarn, Vikash Jha, Jacek Switala, and Peter C. Loewen. 2008. “Comparative Study of Catalase-Peroxidases (KatGs).” Archives of Biochemistry and Biophysics 471 (2): 207–14. https://doi.org/10.1016/j.abb.2007.12.008.
  2. ↑ 2.0 2.1 2.2 2.3 Claiborne, A., and I. Fridovich. 1979. “Purification of the O-Dianisidine Peroxidase from Escherichia Coli B. Physicochemical Characterization and Analysis of Its Dual Catalatic and Peroxidatic Activities.” The Journal of Biological Chemistry 254 (10): 4245–52. https://pubmed.ncbi.nlm.nih.gov/374409.
  3. ↑ “Rhea - Annotated Reactions Database.” n.d. Rhea. Accessed July 26, 2021. https://www.rhea-db.org/rhea/30275. ‌
  4. ↑ “Rhea - Annotated Reactions Database.” n.d. Rhea. Accessed July 26, 2021. https://www.rhea-db.org/rhea/20309. ‌
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//function/degradation
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