info:eu-repo/semantics/article
Tyrosine 9 is the key amino acid in microcin J25 superoxide overproduction
Fecha
2009-11Registro en:
Chalon, Miriam Carolina; Bellomio, Augusto; Solbiati, José O.; Morero, Roberto Dionisio; Farias, Ricardo Norberto; et al.; Tyrosine 9 is the key amino acid in microcin J25 superoxide overproduction; Wiley Blackwell Publishing, Inc; FEMS Microbiology Letters; 300; 1; 11-2009; 90-96
0378-1097
CONICET Digital
CONICET
Autor
Chalon, Miriam Carolina
Bellomio, Augusto
Solbiati, José O.
Morero, Roberto Dionisio
Farias, Ricardo Norberto
Vincent, Paula Andrea
Resumen
Escherichia coli microcin J25 (MccJ25) is a lasso-peptide antibiotic comprising 21 l-amino acid residues (G1-G-A-G-H5-V-P-E-Y- F10-V-G-I-G-T15-P-I-S-F-Y20-G). MccJ25 has two independent substrates: RNA-polymerase (RNAP) and the membrane respiratory chain. The latter is mediated by oxygen consumption inhibition together with an increase of superoxide production. In the present paper, the antibiotic MccJ25 was engineered by substituting Tyr9 or Tyr20 with phenylalanine. Both mutants were well transported into the cells and remained active on RNAP. Only the Y9F mutant lost the ability to overproduce superoxide and inhibit oxygen consumption. The last results confirm that the Tyr 9, and not Tyr20, is involved in the MccJ25 action on the respiratory chain target.