Bioinformatic and enzymatic characterization of the MAPEG superfamily

摘要: The membrane associated proteins in eicosanoid and glutathione metabolism (MAPEG) superfamily includes structurally related with diverse functions of widespread origin. A total 136 belonging to the MAPEG were found database genome screenings. members prokaryotes eukaryotes, but not any archaeal organism. Multiple sequence alignments calculations evolutionary trees revealed a clear subdivision eukaryotic members, corresponding six families microsomal transferases (MGST) 1, 2 3, leukotriene C4 synthase (LTC4), 5-lipoxygenase activating protein (FLAP), prostaglandin E synthase. Prokaryotes contain at least two distinct potential ancestral subfamilies, which one is unique, whereas other most closely resembles enzymes that belong MGST2/FLAP/LTC4 families. insect are similar MGST1/prostaglandin With new data available, we observe fish present all families, showing an early origin for family differentiation. Thus, origins relationships can be defined, including patterns characteristic each subfamilies. We have further investigated functionally characterized representative gene products from Escherichia coli, Synechocystis sp., Arabidopsis thaliana Drosophila melanogaster, liver enzyme, purified pike (Esox lucius). Protein overexpression enzyme activity analysis demonstrated catalyzed conjugation 1-chloro-2,4-dinitrobenzene reduced glutathione. E. coli displayed transferase 0.11 micromol.min(-1).mg(-1) fraction bacteria overexpressing protein. Partial purification sp. yielded expected molecular mass N-terminal amino acid was 50% pure, specific towards 11 micromol.min(-1).mg(-1). Yeast microsomes expressing showed 0.02 micromol.min(-1).mg(-1), expressed highly active 3.6 MGST described so far 285 also peroxidase cumene hydroperoxide (0.4 2.2 respectively). Glutathione thus regarded as common denominator majority throughout kingdoms life occurs representatives MGST1, 3 PGES