• Prosthetic group features
• Catalase reaction
• Catalases in enzyme databases
• Catalases in motif databases
• Catalases in alignment databases
• Catalases in 3­D databases
• References

Haem type	Haem iron coordination	Axial iron ligand(s)	Formal iron oxidation/spin states
Haem b or Haem d (cis­hydroxychlorin ­spirolactone)	Pentacoordinate	OTyr	FeII (S=2); FeIII (S=5/2)
	Hexacoordinate	OTyr; H2O2, O2 or other ligand	FeIII (S=1/2)
	Hexacoordinate	OTyr; O (O·)	FeIV (S=1)

Catalase (hydrogen peroxide:hydrogen peroxide oxidoreductase; EC 1.11.1.6) is a haem­containing enzyme that catalyses the reaction

ROOH + HQOH QO + ROH + H₂O

where R is a hydrogen or an alkyl or acyl group and HQOH is a two­electron donor. Catalases can utilise hydrogen peroxide (H₂O₂) both as an electron acceptor and an electron donor (`catalatic' activity) yielding molecular oxygen (O₂) and water in the disproportionation reaction:

H₂O₂ + H₂O₂ 2H₂O + O₂

(This reaction is also catalysed by bacterial catalase­peroxidases, which belong to the fungal, plant and bacterial haem peroxidase superfamily).

The reaction cycle of the catalases begins with the high­spin ferric (Fe^III) state which reacts with the molecule of peroxide to form compound I intermediate, a porphyrin ­cation radical containing Fe^IV. Next, oxidation of an electron donor returns compound I to the native resting state [1]:

Both the resting state and compound I of catalase are neutral (cf. peroxidases and chloroperoxidase).

The 3­D structures of several catalases have been reported, including Penicillium vitale (PVC) [2], bovine liver (BLC) [3], Micrococcus lysodeikticus (MLC) [4], Proteus mirabilis (PMC) [5] catalases, and Escherichia coli catalase hydroperoxidase II (HPII) [6]. All these enzymes are tetrameric, with a 222 molecular symmetry. Each monomer is an /ß protein, consisting of two main domains: a ß­barrel and an all­ domain (see Figure 1CAF a). PVC and HPII have an additional C­terminal domain with nucleotide­binding topology (Rossmann fold) but no bound nucleotides have been found [6]. On the other hand, BLC, which does not contain this domain, has been shown to bind NADPH [7].

Most catalases have haem b as the prosthetic group; however, a number of fungal and bacterial catalases contain chlorin­type haem (haem d) [8-10]. A haem d with the configuration of a cis­hydroxychlorin ­spirolactone has been found in the crystal structures of PVC and HPII; haem d is believed to be formed from haem b in the interior of the catalase molecule through a self­catalysed reaction [11]. For both PVC and HPII, the haem d is rotated 180° around the axis defined by the -­meso carbon atoms with respect to the orientation of haem b in BLC. In all catalases the haem iron fifth (proximal) ligand is a Tyr residue; the His residue essential for catalysis is located on the distal side of the haem. In all catalase structures, a water molecule located close to the sixth co­ordination of the haem has been observed [3-6] (see Figure 1CAF b).

Catalases in enzyme databases

ENZYME	LIGAND	BRENDA	Official name	Alternative name
1.11.1.6	1.11.1.6	1.11.1.6	Catalase	Hydrogen peroxide:hydrogen peroxide oxidoreductase

Catalases in motif databases

PRINTS ID	PRINTS AC	PROSITE/BLOCKS ID	PROSITE AC	BLOCKS AC
CATALASE	PR00067	CATALASE_1 CATALASE_2	PS00437 PS00438	BL00437

Catalases in alignment databases

Protein Superfamily	Pfam	LPFC 3­D alignment
00168; catalase 60701; catalase	PF00199; catalase	-

PDB	scop	BSM	RELI Base	Header	¹
1iph*	1iph*	1iph*	1iph*	Catalase HPII; Escherichia coli	MS6LBC56*
2cae	2cae	2cae	2cae	Catalase (residue 53 is a methionine sulphone); Proteus mirabilis (peroxide resistant mutant)	MS6MMC8
2caf	2caf	2caf	2caf	Catalase (compound I) (residue 53 is a methionine sulphone); Proteus mirabilis (peroxide resistant mutant)	MS6MMC8
2cag	2cag	2cag	2cag	Catalase (compound II) (residue 53 is a methionine sulphone); Proteus mirabilis (peroxide resistant mutant)	-
2cah	2cah	2cah	2cah	Catalase (native form) (complex with NADPH) (residue 53 is a methionine sulphone); Proteus mirabilis (peroxide resistant mutant)	-
4cat*	4cat*	4cat*	4cat*	Catalase; Penicillium vitale	-
7cat	7cat	7cat	7cat	Catalase (complex with NADPH); bovine (Bos taurus) liver	-
8cat	8cat	8cat	8cat	Catalase (complex with NADPH); bovine (Bos taurus) liver	-
-	s083	-	-	Catalase; Micrococcus lysodeikticus (syn. Micrococcus luteus)	MMS93037

¹ Macromolecular Structures abstract. Full text is available to BioMedNet Members

References

1. Andersson, L.A. and Dawson, L.A. (1991) EXAFS spectroscopy of heme­containing oxygenases and peroxidases. Structure and Bonding 64, 1-40.
2. Vainshtein, B.K., Melik­Adamyan, W.R., Barynin, V.V., Vagin, A.A., Grebenko, A.I., Borisov, V.V., Bartels, K.S., Fita, I. and Rossmann, M.G. (1986) Three­dimensional structure of catalase from Penicillium vitale at 2.0 Å resolution. J. Mol. Biol. 188, 49-61.
3. Fita, I., Silva, A.M., Murthy, M.R.N. and Rossmann, M.G. (1986) The refined structure of beef liver catalase at 2.5 Å resolution. Acta Crystallogr. B42, 497-515.
4. Murshudov, G.N., Melik­Adamyan, W.R., Grebenko, A.I., Barynin, V.V., Vagin, A.A., Vainshtein, B.K., Dauter, Z. and Wilson, K.S. (1992) Three­dimensional structure of catalase from Micrococcus lysodeikticus at 1.5 Å resolution. FEBS Lett. 312, 127-131.
5. Gouet, P., Jouve, H.­M. and Dideberg, O. (1995) Crystal structure of Proteus mirabilis PR catalase with and without bound NADPH. J. Mol. Biol. 249, 933-954.
6. Bravo, J., Verdaguer, N., Tormo, J., Betzel, C., Switala, J., Loewen, P.C. and Fita, I. (1995) Crystal structure of catalase HPII from Escherichia coli. Structure 3, 491-502.
7. Fita, I. and Rossmann, M.G. (1985) The NADPH binding site on beef liver catalase. Proc. Natl. Acad. Sci. USA 82, 1604-1608.
8. Jacob, G.S. and Orme­Johnson, W.H. (1979) Catalase of Neurospora crassa. 2. Electron paramagnetic resonance and chemical properties of the prosthetic group. Biochemistry 18, 2975-2980.
9. Goldberg, I. and Hochman, A. (1989) Three different types of catalases in Klebsiella pneumoniae. Arch. Biochem. Biophys. 268, 124-128.
10. Chiu, J.T., Loewen, P.C., Switala, J., Gennis, R.B. and Timkovich, R. (1989) Proposed structure for the prosthetic group of the catalase HPII from Escherichia coli. J. Am. Chem. Soc. 111, 7046-7050.
11. Murshudov, G.N., Grebenko, A.I., Barynin, V.V., Dauter, Z., Wilson, K.S., Vainshtein, B.K., Melik­Adamyan, W.R., Bravo, J., Ferrán, J.M., Ferrer, J.C., Switala, J., Loewen, P.C. and Fita, I. (1996) Structure of the heme d of Penicillium vitale and Escherichia coli catalases. J. Biol. Chem. 271, 8863-8868.

Bibliography on structural studies of catalases