title: Inhibition by penem of processing peptidases from cyanobacteria and chloroplast thylakoids.
abstract: Proteins targeted to the thylakoid lumen of plants and cyanobacteria and the periplasmic space of cyanobacteria are synthesised with N-terminal presequences which are removed following translocation across the membrane. These presequences are thought to direct translocation of the preprotein by a sec-type pathway. Detergent extracts of cyanobacterial and chloroplast membranes contain enzymes which are capable of processing precursors to the mature size. We show that the processing of a range of precursors by both cyanobacterial and chloroplast enzymes is inhibited by the penem SB216357. This is the first report of an inhibitor of these enzymes and indicates that they are type 1 signal peptidases.
authors.affiliation: Department of Biochemistry and Cambridge Centre for Molecular Recognition, University of Cambridge, UK.
authors.forename: A C
authors.initials: AC
authors.lastname: Barbrook
authors.forename: J C
authors.initials: JC
authors.lastname: Packer
authors.forename: C J
authors.initials: CJ
authors.lastname: Howe
mesh_terms: D002736:Chloroplasts / Q000187:drug effects / Q000201:enzymology*; D000458:Cyanobacteria / Q000187:drug effects / Q000201:enzymology*; D010450:Endopeptidases / Q000378:metabolism*; D007769:Lactams / Q000494:pharmacology*; D018532:Pisum sativum / Q000201:enzymology; D045322:Photosynthetic Reaction Center Complex Proteins / Q000378:metabolism; D010970:Plastocyanin / Q000378:metabolism; D011480:Protease Inhibitors / Q000494:pharmacology*; D011498:Protein Precursors / Q000378:metabolism*; D011499:Protein Processing, Post-Translational / Q000187:drug effects*
chemical_list: D007769:Lactams; D045322:Photosynthetic Reaction Center Complex Proteins; D011480:Protease Inhibitors; D011498:Protein Precursors; C103261:SB 216357; D010970:Plastocyanin; D010450:Endopeptidases; C069654:thylakoid processing peptidase