Nucleotide sequence of Escherichia coli katE, which encodes catalase HPII

Abstract

A 3,466-bp nucleotide sequence containing the katE gene of Escherichia coli has been determined. An open reading frame of 2,259 bp was found and was preceded by a potential ribosome-binding site. The predicted N-terminal sequence agreed with the sequence determined by direct amino acid sequencing, and the predicted direction of transcription was confirmed by expression of the gene cloned in both directions behind a T7 promoter. The start site of transcription was determined to be 127 bp upstream from the start of the open reading frame, and a potential RNA polymerase-binding site similar to a sequence preceding the xthA gene, which is also controlled by the KatF protein, was identified. The predicted sequence of the 753-amino-acid protein was comnpared with known sequences of other catalases, revealing significant similarity to the shorter catalases, including the residues in the putative active site and residues involved in heme binding.Escherichia coli produces two catalases, a bifunctional catalase-peroxidase (hydroperoxidase I [HPI]) and a monofunctional catalase (HPII). Both enzymes have been purified and characterized to be quite different from each other and from the typical catalase, which is active as a tetramer of 65,000-Da subunits and four protoheme IX groups. HPI was found to be a tetramer of 78,000-Da subunits with just two protoheme IX groups per tetramer and with an associated broad-spectrum peroxidase activity (6). HPII was purified (7) and characterized as a hexamer of 93,000-Da subunits (18) and six heme d-like groups (5) per hexamer. The genes encoding HPI and HPII, katG and katE, respectively, are unlinked, mapping at 89.2 (21) and 37.2 (17) min, respectively. A third gene, katF, mapping at 59.0 min (20), was found to be required for expression of katE but not katG. The katF gene has been cloned (28) and sequenced (27), revealing a striking similarity between the KatF protein and known sigma transcription factors, suggesting its mechanism as a positive effector of katE (27), of xthA (32), and possibly of other genes involved in resistance to near-UV radiation (33).The katG gene has been cloned (22, 42) and sequenced (41) and predicts an amino acid sequence that bears no resemblance to any of the known catalase sequences. Instead, a striking resemblance to a peroxidase from Bacillus stearothermophilus has been observed (23), suggesting that the bifunctional HPI is more closely related to the family of peroxidases than catalases. On the basis of its very different physical structure, it seemed unlikely that HPII would have any sequence or structural similarity to the common catalases. This paper describes the sequence analysis of katE, the identification of the site of transcription initiation, and a comparison of the predicted amino acid sequence of HPII with the sequences of other catalases. MATERIALS AND METHODSBacterial strains and plasmids. The strains JM101 (45) and NM522 (25) were used for plasmid preparations and for the preparation of single-stranded DNA for sequencing. Cul-* Correspo...

Heterologous growth phase- and temperature-dependent expression and H2O2 toxicity protection of a superoxide-inducible monofunctional catalase gene from Xanthomonas oryzae pv. oryzae

“…Identities of greater than 50% were observed between KatX and catalases from bovine, maize, Listeria seeligeri (17), Lactobacillus sake (26), Pseudomonas syringae, and Bacillus subtilis (5). More importantly, all amino acid residues involved in the active site (i.e., His-128, Ser-167, and Asn-201 in KatE and His-89, Ser-128, and Asn-162 in KatX) and in heme binding (i.e., Val-127, Thr-168, Phe-206, and Phe-214 in KatE and Val-88, Thr-129, Phe-167, and Phe-175 in KatX on the distal side of the heme and Pro-393, Arg-411, and Tyr-415 in KatE and Pro-354, Arg-372, and Tyr-376 in KatX on the proximal side of the heme) were highly conserved (47).…”

“…The amino acid residues involved in binding these molecules (His-304 for binding the pyrophosphate group of NADPH and His-234, Lys-236, and Tyr-214 for binding water) have been established in bovine catalase. von Ossowski et al (47) studied differences in amino acid residues at the binding sites of these molecules in E. coli HPII (KatE) and other proteins. They found that the presence of Glu-362 in KatE in an analogous location to His-304 in bovine catalase made binding of the negatively charged pyrophosphate groups of NADPH to the negatively charged Glu-362 unlikely.…”

“…Each enzyme is encoded by a different gene (e.g., in Escherichia coli, katE and katG code for monofunctional and bifunctional catalases, respectively) (35,45). Monofunctional catalases share regions of an amino acid sequence that is highly conserved among microbial, plant, and mammalian enzymes (5,26,47). In many bacteria, the two kat genes are regulated differently in terms of growth phase and response to oxidative stress, suggesting that they may have different physiological functions (10,23,29).…”

An Electrical Potential in the Access Channel of Catalases Enhances Catalysis

“…Strains and Plasmids-The plasmid pAMkatE72 (22) was used as the source for the katE gene. Phagemids pKSϩ and pKSϪ from Stratagene Cloning Systems were used for mutagenesis, sequencing, and cloning.…”

Nucleotide sequence of the Mycobacterium leprae katG region

“…HPI (encoded by katG) is a prokaryotic broadspectrum bifunctional peroxidase-catalase inducible by hydrogen peroxide (7). The E. coli catalase HPII (encoded by katE) is a monofunctional enzyme that has sequence similarities to eukaryotic catalase (17). Biochemical and serological characterizations of mycobacterial lysates have also identified two mycobacterial catalases (20).…”