title: The Role of a Nonribosomal Peptide Synthetase in l-Lysine Lactamization During Capuramycin Biosynthesis.
abstract: Capuramycins are one of several known classes of natural products that contain an l-Lys-derived l-α-amino-ɛ-caprolactam (l-ACL) unit. The α-amino group of l-ACL in a capuramycin is linked to an unsaturated hexuronic acid component through an amide bond that was previously shown to originate by an ATP-independent enzymatic route. With the aid of a combined in vivo and in vitro approach, a predicted tridomain nonribosomal peptide synthetase CapU is functionally characterized here as the ATP-dependent amide-bond-forming catalyst responsible for the biosynthesis of the remaining amide bond present in l-ACL. The results are consistent with the adenylation domain of CapU as the essential catalytic component for l-Lys activation and thioesterification of the adjacent thiolation domain. However, in contrast to expectations, lactamization does not require any additional domains or proteins and is likely a nonenzymatic event. The results set the stage for examining whether a similar NRPS-mediated mechanism is employed in the biosynthesis of other l-ACL-containing natural products and, just as intriguingly, how spontaneous lactamization is avoided in the numerous NRPS-derived peptides that contain an unmodified l-Lys residue.
authors: Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, Lexington, KY, 40536, USA.
authors: Xiaodong
authors: X
authors: Liu
authors: Key Laboratory of Biotechnology of Antibiotics, Institute of Medicinal Biotechnology, Chinese Academy of Medicinal Sciences & Peking Union Medical College, Beijing, China.
authors: Yuanyuan
authors: Y
authors: Jin
authors: Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, Lexington, KY, 40536, USA.
authors: Zheng
authors: Z
authors: Cui
authors: Biologics Technology Research Laboratories, Daiichi Sankyo, Co. Ltd., Gunma, 370-0503, Japan.
authors: Koichi
authors: K
authors: Nonaka
authors: Biologics Technology Research Laboratories, Daiichi Sankyo, Co. Ltd., Gunma, 370-0503, Japan.
authors: Satoshi
authors: S
authors: Baba
authors: Natural Product Research Group, Discovery Science and Technology Department, Daiichi Sankyo RD Novare Co. Ltd., Tokyo, 134-8630, Japan.
authors: Masanori
authors: M
authors: Funabashi
authors: Key Laboratory of Biotechnology of Antibiotics, Institute of Medicinal Biotechnology, Chinese Academy of Medicinal Sciences & Peking Union Medical College, Beijing, China.
authors: Zhaoyong
authors: Z
authors: Yang
authors: Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, Lexington, KY, 40536, USA. svanlanen@uky.edu.
authors: Steven G
authors: 0000-0003-1539-2732
authors: SG
authors: Van Lanen
mesh_terms: D000617:Aminoglycosides / Q000096:biosynthesis* / Q000737:chemistry; D002209:Caprolactam / Q000737:chemistry / Q000378:metabolism; D002851:Chromatography, High Pressure Liquid; D008239:Lysine / Q000378:metabolism*; D010453:Peptide Synthases / Q000235:genetics / Q000378:metabolism*; D013302:Streptomyces / Q000201:enzymology / Q000235:genetics
chemical_list: D000617:Aminoglycosides; C049983:capuramycin; D002209:Caprolactam; D010453:Peptide Synthases; C104385:non-ribosomal peptide synthase; D008239:Lysine
keywords: antibiotics; biosynthesis; natural products; nonribosomal peptides; nucleosides