title: Dissecting the complete lipoprotein biogenesis pathway in Streptomyces scabies.
abstract: Following translocation, bacterial lipoproteins are lipidated by lipoprotein diacylglycerol transferase (Lgt) and cleaved of their signal peptides by lipoprotein signal peptidase (Lsp). In Gram-negative bacteria and mycobacteria, lipoproteins are further lipidated by lipoprotein N-acyl transferase (Lnt), to give triacylated lipoproteins. Streptomyces are unusual amongst Gram-positive bacteria because they export large numbers of lipoproteins via the twin arginine protein transport (Tat) pathway. Furthermore, some Streptomyces species encode two Lgt homologues and all Streptomyces species encode two homologues of Lnt. Here we characterize lipoprotein biogenesis in the plant pathogen Streptomyces scabies and report that lgt and lsp mutants are defective in growth and development while only moderately affected in virulence. Lipoproteins are lost from the membrane in an S. scabies lgt mutant but restored by expression of Streptomyces coelicolor lgt1 or lgt2 confirming that both encode functional Lgt enzymes. Furthermore, lipoproteins are N-acylated in Streptomyces with efficient N-acylation dependent on Lnt1 and Lnt2. However, deletion of lnt1 and lnt2 has no effect on growth, development or virulence. We thus present a detailed study of lipoprotein biogenesis in Streptomyces, the first study of Lnt function in a monoderm bacterium and the first study of bacterial lipoproteins as virulence factors in a plant pathogen.
authors.affiliation: School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ, UK.
authors.forename: David A
authors.initials: DA
authors.lastname: Widdick
authors.forename: Matthew G
authors.initials: MG
authors.lastname: Hicks
authors.forename: Benjamin J
authors.initials: BJ
authors.lastname: Thompson
authors.forename: Andreas
authors.initials: A
authors.lastname: Tschumi
authors.forename: Govind
authors.initials: G
authors.lastname: Chandra
authors.forename: Iain C
authors.initials: IC
authors.lastname: Sutcliffe
authors.forename: Juliane K
authors.initials: JK
authors.lastname: Brülle
authors.forename: Peter
authors.initials: P
authors.lastname: Sander
authors.forename: Tracy
authors.initials: T
authors.lastname: Palmer
authors.forename: Matthew I
authors.initials: MI
authors.lastname: Hutchings
mesh_terms: D001426:Bacterial Proteins / Q000096:biosynthesis* / Q000737:chemistry / Q000235:genetics; D053898:Biosynthetic Pathways; D015180:Electrophoresis, Gel, Two-Dimensional; D008074:Lipoproteins / Q000096:biosynthesis* / Q000737:chemistry / Q000235:genetics; D013058:Mass Spectrometry; D009154:Mutation; D010935:Plant Diseases / Q000382:microbiology; D031224:Raphanus / Q000382:microbiology; D011198:Solanum tuberosum / Q000382:microbiology; D013302:Streptomyces / Q000737:chemistry / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D008074:Lipoproteins