Catalase

Catalase (CAT) catalyzes the conversion of hydrogen peroxide to water and oxygen. CAT contains porphyrin-heme Fe group which reacts with the hydrogen peroxide. CAT containing Mn are called pseudocatalase (PCAT). Catalase-peroxidase (CAT KatG) is a bifunctional enzyme with both catalase and peroxidase activities. CAT KatG cofactor is a group. It provides defense against oxidative stress by reducing hydrogen peroxide. Mutations in CAT KatG can cause resistance to the anti-malarial drug isoniazid (INH). Catalase-phenol oxidase (CATPO) is a heme-containing CAT which shows phenol oxidase activity.

Catalase is a tetramer of four polypeptide chains, each over 500 amino acids long. It contains four porphyrin heme (iron) groups that allow the enzyme to react with the hydrogen peroxide.

As hydrogen peroxide enters the active site, it interacts with the amino acids Asn147 (asparagine at position 147) and His74, causing a proton (hydrogen ion) to transfer between the oxygen atoms. The free oxygen atom coordinates, freeing the newly formed water molecule and Fe(IV)=O. Fe(IV)=O reacts with a second hydrogen peroxide molecule to reform Fe(III)-E and produce water and oxygen.[13] The reactivity of the iron center may be improved by the presence of the phenolate ligand of Tyr357 in the fifth iron ligand, which can assist in the oxidation of the Fe(III) to Fe(IV). The efficiency of the reaction may also be improved by the interactions of His74 and Asn147 with reaction intermediates.

3D Structures of catalase3D Structures of catalase

Updated on 19-November-2014

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• catalase
  • 1qqw, 1dgb, 1dgf, 1f4j – hCAT - human
    
  • 4cat – CAT – Penicillium janthinellum
    
  • 1iph, 1gge, 1ye9, 4bfl – EcCAT Hpii – Escherichia coli
    
  • 1u2j, 1u2k – EcCAT Hpi C terminal
    
  • 1u2l – EcCAT KatG
    
  • 1cf9, 1qf7, 1gg9, 1ggh, 1ggj, 1ggk, 1p7y, 1p7z, 1p80, 1p81, 1qws, 3p9p, 3p9q, 3p9r, 3p9s, 3pq2, 3pq3, 3pq4, 3pq5, 3pq6, 3pq7, 3pq8, 3ttt, 3ttu, 3ttv, 3ttw, 3ttx, 4enp, 4enq, 4enr, 4ens, 4ent, 4enu, 4env, 4enw - EcCAT Hpii (mutant)
    
  • 4blc, 1tgu, 1th3, 3nwl – bCAT – Bovine
    
  • 1a4e – CAT A – yeast
    
  • 2cag, 1e93, 1m85, 1mqf, 1h7k – PmCAT – Proteus mirabilis
    
  • 1h6n, 3hb6 - PmCAT (mutant)
    
  • 1hbz, 1gwe, 1gwf – MlCAT – Micrococcus lysodeikticus
    
  • 1m7s – CAT CatF – Pseudomonas syringae
    
  • 1qwl, 2iqf – HpCAT – Helicobacter pylori
    
  • 1si8 – CAT – Enterococcus Faecalis
    
  • 1sj2, 2cca – MtCAT KatG – Mycobacterium tuberculosis
    
  • 2ccd, 4c50, 4c51 - MtCAT KatG (mutant)
    
  • 1ub2 – CAT – Synechococcus elongatus
    
  • 1mwv, 2b2o, 2b2q, 2fxg, 2fxh, 2fxj – BpCAT KatG – Burkholderia pseudomallei
    
  • 1x7u, 2dv1, 2dv2, 3n3r - BpCAT KatG (mutant)
    
  • 1itk, 2a9e, 3n3s, 3uw8 – HmCAT KatG – Haloarcula marismortui
    
  • 3vlh, 3vlk, 3vlm – HmCAT KatG (mutant)
    
  • 1sy7 – NcCAT-1 – Neurospora crassa
    
  • 3ej6, 3zj4, 3zj5, 4aj9, 4bim – NcCAT-3
    
  • 2j2m – CAT – Exiguobacterium oxidotolerans
    
  • 2isa – CAT – Vibrio salmonicida
    
  • 2xf2 - 2iuf – PjCAT – Penicillium janthinellum
    
  • 2xq1 – CAT – Pichia angusta
    
  • 4e37 – CAT – Pseudomonas aeruginosa
    
  • 3ut2 – CAT – rice blast fungus
    
• Catalase binary complexes
  • 7cat, 8cat – bCAT + NADPH
    
  • 2cah - PmCAT + NADPH
    
  • 1gwh - MlCAT + NADPH
    
  • 3n3o - BpCAT KatG + NAD
    
  • 1nm0 – PmCAT + formiate
    
  • 1qwm - HpCAT + formic acid
    
  • 1dgg – hCAT + CN
    
  • 3vli, 3vlj - HmCAT KatG (mutant) + CN
    
  • 3vll - HmCAT KatG (mutant) + salicylhydroxamic acid
    
  • 1th2 – bCAT + N3
    
  • 3rgp, 3re8 – bCAT + NO
    
  • 3rgs – bCAT + NH3
    
  • 2b2r, 2b2s - BpCAT KatG + O
    
  • 2iuf – PjCAT + O
    
  • 3n3n - BpCAT KatG + INH
    
  • 3n3p - BpCAT KatG + INH + AMP
    
  • 3n3q - BpCAT KatG + INH
    
  • 3n3h - BpCAT KatG (mutant) + INH
    
  • 1dgh – hCAT + amino-triazole
    
  • 1th4 - bCAT + amino-triazole
    
  • 1ggf - EcCAT Hpii (mutant) + H2O2
    
  • 3vu3 – EcCAT Hpii + HFQ
    
  • 4b7f, 4b7h – CgCAT + NADPH + NO – Corynebacterium glutamicum
    
  • 4b7g – CgCAT + NADPH
    
• Pseudocatalase Mn-containing
  • 1jku – LpPCAT-Mn – Lactobacillus plantarum
    
  • 1o9i – LpPCAT-Mn (mutant)
    
  • 2cwl – TtPCAT-Mn Mn-free – Thermus thermophilus
    
  • 2v8u - TtPCAT-Mn
    
  • 2v8t - TtPCAT-Mn + chloride
    
  • 1jkv - LpPCAT-Mn + N3
    
• Catalase-phenol oxidase
  • 4aue, 4aul, 4aum, 4aun, 4b2y, 4b31, 4b40, 4b5k, 4b7a - CATPO - Scytalidium thermophilum