tailieunhanh - Báo cáo khoa học: Role of DptE and DptF in the lipidation reaction of daptomycin

c-Tubulin belongs to the tubulin superfamily and plays an essential role in the nucleation of cellular microtubules. In the present study, we report the characterization ofc-tubulin from the psychrophilic Antarctic ciliate Eupl-otes this organism,c-tubulin is encoded by two genes, c-T1 and c-T2, that produce distinct isotypes. | IFEBS Journal Role of DptE and DptF in the lipidation reaction of daptomycin Melanie Wittmann Uwe Linne Verena Pohlmann and Mohamed A. Marahiel Department of Chemistry Biochemistry Philipps-University Marburg Germany Keywords acidic lipopeptide antibiotics AMP ligase daptomycin lipidation reaction nonribosomal peptide synthetases Correspondence M. A. Marahiel Department of Chemistry Biochemistry Philipps-University Marburg Hans-Meerwein-Strasse D-35043 Marburg Germany Fax 49 6421 2822191 Tel 49 6241 2825722 E-mail marahiel@ Received 4 June 2008 revised 29 August 2008 accepted 1 September 2008 doi Daptomycin and A21987C antibiotics are branched cyclic nonribosomally assembled acidic lipodepsipeptides produced by Streptomyces roseosporus. The antibacterial activity of daptomycin against Gram-positive bacteria strongly depends on the nature of the N-terminal fatty acid moiety. Two genes dptE and dptF localized upstream of the daptomycin nonribosomal peptide synthetase genes are thought to be involved in the lipidation of daptomycin. Here we describe the cloning heterologous expression purification and biochemical characterization of the enzymes encoded by these genes. DptE was proven to preferentially activate branched mid- to long-chain fatty acids under ATP consumption and these fatty acids are subsequently transferred onto DptF the cognate acyl carrier protein. Additionally we demonstrate that lipidation of DptF by DptE in trans is based on specific protein-protein interactions as DptF is favored over other acyl carrier proteins. Study of DptE and DptF may provide useful insights into the lipidation mechanism and these enzymes may be used to generate novel daptomycin derivatives with altered fatty acids. Daptomycin is a clinically important semi-synthetic derivative of the A21978C branched cyclic lipopeptide antibiotics produced by Streptomyces roseosporus 1 . Acidic lipopeptide antibiotics present a new class .