The structural gene for microcin H47 encodes a peptide precursor with antibiotic activity.
Microcin H47 is a bactericidal antibiotic produced by a naturally occurring Escherichia coli strain isolated in Uruguay. The microcin genetic system is located in the chromosome and extends over a 10-kb DNA segment containing the genes required for microcin synthesis, secretion, and immunity. The smallest microcin synthesis gene, mchB, was sequenced and shown to encode a highly hydrophobic peptide. An mchB-phoA gene fusion, which directed the synthesis of a hybrid bifunctional protein with both PhoA and microcin H47-like activities, was isolated. The results presented herein lead us to propose that microcin H47 is indeed a ribosomally synthesized peptide antibiotic and that its peptide precursor already has antibiotic activity of the same specificity as that of mature microcin.
Rodríguez
E
E
Sección de Fisiología y Genética Bacterianas, Facultad de Ciencias, Iguá 4225, Malvín Norte, Montevideo, Uruguay.
Gaggero
C
C
Laviña
M
M
D000595:Amino Acid Sequence; D000900:Anti-Bacterial Agents / Q000096:biosynthesis*; D001430:Bacteriocins / Q000096:biosynthesis / Q000235:genetics*; D001483:Base Sequence; D002478:Cells, Cultured; D005798:Genes, Bacterial; D008969:Molecular Sequence Data; D010455:Peptides; D010957:Plasmids / Q000235:genetics; D012270:Ribosomes / Q000378:metabolism
D000900:Anti-Bacterial Agents; D001430:Bacteriocins; D010455:Peptides; C020411:microcin