Structural highlights
Function
IPNA_EMENI Isopenicillin N synthase; part of the gene cluster that mediates the biosynthesis of penicillin, the world's most important antibiotic (PubMed:3319778, PubMed:11755401). IpnA catalyzes the cyclization of the tripeptide N-[(5S)-5-amino-5-carboxypentanoyl]-L-cysteinyl-D-valine (LLD-ACV or ACV) to form isopenicillin N (IPN) that contains the beta-lactam nucleus (PubMed:3319778, PubMed:11755401, PubMed:28703303). The penicillin biosynthesis occurs via 3 enzymatic steps, the first corresponding to the production of the tripeptide N-[(5S)-5-amino-5-carboxypentanoyl]-L-cysteinyl-D-valine (LLD-ACV or ACV) by the NRPS acvA. The tripeptide ACV is then cyclized to isopenicillin N (IPN) by the isopenicillin N synthase ipnA that forms the beta-lactam nucleus. Finally, the alpha-aminoadipyl side chain is exchanged for phenylacetic acid by the isopenicillin N acyltransferase penDE to yield penicillin in the peroxisomal matrix (By similarity).[UniProtKB:P08703][1] [2] [3]
Evolutionary Conservation
Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.
Publication Abstract from PubMed
Isopenicillin N synthase (IPNS) is a non-heme iron(II) oxidase which catalyses the biosynthesis of isopenicillin N (IPN) from the tripeptide delta-l-alpha-aminoadipoyl-l-cysteinyl-d-valine (lld-ACV). Herein we report crystallographic studies to investigate the binding of a truncated lll-substrate in the active site of IPNS. Two epimeric tripeptides have been prepared by solution phase peptide synthesis and crystallised with the enzyme. delta-l-alpha-Aminoadipoyl-l-cysteinyl-d-2-amino-3,3-dideuteriobutyrate (lld-ACd(2)Ab) has the same configuration as the natural substrate lld-ACV at each of its three stereocentres; its epimer delta-l-alpha-aminoadipoyl-l-cysteinyl-l-2-amino-3,3-dideuteriobutyrate (lll-ACd(2)Ab) has the opposite configuration at its third amino acid. lll-ACV has previously been shown to inhibit IPNS turnover of its substrate lld-ACV; the all-protiated tripeptide delta-l-alpha-aminoadipoyl-l-cysteinyl-d-2-aminobutyrate (lld-ACAb) is a substrate for IPNS, being turned over to a mixture of penam and cepham products. Comparisons between the crystal structures of the IPNS:Fe(II):lld-ACd(2)Ab and IPNS:Fe(II):lll-ACd(2)Ab complexes offer a possible rationale for the previously observed inhibitory effects of lll-ACV on IPNS activity.
Crystallographic studies on the binding of selectively deuterated LLD- and LLL-substrate epimers by isopenicillin N synthase.,Ge W, Clifton IJ, Stok JE, Adlington RM, Baldwin JE, Rutledge PJ Biochem Biophys Res Commun. 2010 Aug 6;398(4):659-64. Epub 2010 Jul 13. PMID:20603104[4]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Ogle JM, Clifton IJ, Rutledge PJ, Elkins JM, Burzlaff NI, Adlington RM, Roach PL, Baldwin JE. Alternative oxidation by isopenicillin N synthase observed by X-ray diffraction. Chem Biol. 2001 Dec;8(12):1231-7. PMID:11755401
- ↑ McNeill LA, Brown TJN, Sami M, Clifton IJ, Burzlaff NI, Claridge TDW, Adlington RM, Baldwin JE, Rutledge PJ, Schofield CJ. Terminally Truncated Isopenicillin N Synthase Generates a Dithioester Product: Evidence for a Thioaldehyde Intermediate during Catalysis and a New Mode of Reaction for Non-Heme Iron Oxidases. Chemistry. 2017 Sep 18;23(52):12815-12824. doi: 10.1002/chem.201701592. Epub 2017, Aug 21. PMID:28703303 doi:http://dx.doi.org/10.1002/chem.201701592
- ↑ Ramon D, Carramolino L, Patino C, Sanchez F, Penalva MA. Cloning and characterization of the isopenicillin N synthetase gene mediating the formation of the beta-lactam ring in Aspergillus nidulans. Gene. 1987;57(2-3):171-81. doi: 10.1016/0378-1119(87)90120-x. PMID:3319778 doi:http://dx.doi.org/10.1016/0378-1119(87)90120-x
- ↑ Ge W, Clifton IJ, Stok JE, Adlington RM, Baldwin JE, Rutledge PJ. Crystallographic studies on the binding of selectively deuterated LLD- and LLL-substrate epimers by isopenicillin N synthase. Biochem Biophys Res Commun. 2010 Aug 6;398(4):659-64. Epub 2010 Jul 13. PMID:20603104 doi:10.1016/j.bbrc.2010.06.129
