Amythiamicin A/B Amycolatopsis Sp. Recombinant Protein

Function: Has bacteriocidal activity against Gram-positive bacteria including multi-drug resistant strains such as Staphylococcus aureus MS9610 and Methicillin-resistant S.aureus, but is not active against most Gram-negative bacteria and fungi. Ref.1

Subcellular location: Secreted Ref.1.

Post-translational modification: Maturation of thiazole and oxazole containing antibiotics involves the enzymic condensation of a Cys, Ser or Thr with the alpha-carbonyl of the preceding amino acid to form a thioether or ether bond, then dehydration to form a double bond with the alpha-amino nitrogen. Thiazoline or oxazoline rings are dehydrogenated to form thiazole or oxazole rings.Maturation of pyridinyl containing antibiotics involves the cross-linking of a Ser and a Cys-Ser pair usually separated by 7 or 8 residues along the peptide chain. The Ser residues are dehydrated to didehydroalanines, then bonded between their beta carbons. The alpha carbonyl of the Cys condenses with the alpha carbon of the first Ser to form a pyridinyl ring. The ring may be multiply dehydrogenated to form a pyridine ring with loss of the amino nitrogen of the first Ser.The diketopiperazine ester in form C may be formed by cyclization and transesterification of the C-terminal dipeptide.

Sequence similarities: Belongs to the thiocillin family.

Caution: It is possible that the 5-methylthiazole shown as derived from Cys-4 may be instead derived from Thr.

Mass spectrometry: Molecular mass is 1182.2463 Da from positions 1 - 14. Determined by FAB. Form A. Ref.1Molecular mass is 1200.2549 Da from positions 1 - 14. Determined by FAB. Form B. Ref.1Molecular mass is 1183.2285 Da from positions 1 - 12. Determined by FAB. Form C. Ref.1Molecular mass is 1031.1688 Da from positions 1 - 12. Determined by FAB. Form D. Ref.1