Complete amino acid sequence of Proteus mirabilis PR catalase. Occurrence of a methionine sulfone in the close proximity of the active site.
The catalase of Proteus mirabilis PR, a peroxide-resistant (PR) mutant of Proteus mirabilis, binds strongly NADPH, which is a unique property among known bacterial catalases. The enzyme subunit consists of 484 amino acid residues for a mass of 55,647 daltons. The complete amino acid sequence was resolved through the combination of protein sequencing, mass spectrometry, and nucleotide sequencing of a PCR fragment. The sequence obtained was compared with that of other known catalases. Amino acids of the active site are all conserved as well as essential residues involved in NADPH binding. Among the amino acids interacting with the heme, a methionine sulfone was found at position 53, in place of a valine in most other catalases. The origin of oxidation of this methionine is unknown, but the presence of this modification could change iron accessibility by large substrates or inhibitors. This posttranslational modification was also demonstrated in the wild-type P. mirabilis catalase.
Buzy
A
A
Institut de Biologie Structurale, CEA and CNRS, Grenoble, France.
Bracchi
V
V
Sterjiades
R
R
Chroboczek
J
J
Thibault
P
P
Gagnon
J
J
Jouve
H M
HM
Hudry-Clergeon
G
G
D000595:Amino Acid Sequence; D001483:Base Sequence; D001665:Binding Sites; D002374:Catalase / Q000737:chemistry*; D013058:Mass Spectrometry; D008715:Methionine / Q000031:analogs & derivatives* / Q000032:analysis; D008969:Molecular Sequence Data; D008970:Molecular Weight; D009154:Mutation; D009249:NADP / Q000378:metabolism; D011499:Protein Processing, Post-Translational; D011513:Proteus mirabilis / Q000201:enzymology*; D016415:Sequence Alignment; D017421:Sequence Analysis; D017386:Sequence Homology, Amino Acid
C018332:methionine sulfone; D009249:NADP; D008715:Methionine; D002374:Catalase