1w05

Isopenicillin N Synthase Aminoadipoyl-Cysteinyl-Alanine-Fe ComplexIsopenicillin N Synthase Aminoadipoyl-Cysteinyl-Alanine-Fe Complex

Structural highlights 1w05 is a 1 chain structure with sequence from A. nidulans. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Ligands: , , Related: 1bk0, 1blz, 1hb1, 1hb2, 1hb3, 1hb4, 1ips, 1obn, 1oc1, 1odm, 1odn, 1qiq, 1qje, 1qjf, 1uzw, 1w03, 1w04, 1w06 Gene: PCB C (A. nidulans) Activity: Isopenicillin-N synthase, with EC number 1.21.3.1 Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function [IPNS_EMENI] Removes, in the presence of oxygen, 4 hydrogen atoms from delta-L-(alpha-aminoadipyl)-L-cysteinyl-D-valine (ACV) to form the azetidinone and thiazolidine rings of isopenicillin. 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), a non-heme iron(II)-dependent oxidase, catalyzes conversion of the tripeptide delta-(l-alpha-aminoadipoyl)-l-cysteinyl-d-valine (ACV) to bicyclic isopenicillin N (IPN), concomitant with the reduction of dioxygen to two molecules of water. Incubation of the "truncated"substrate analogues delta-(l-alpha-aminoadipoyl)-l-cysteinyl-glycine (ACG) and delta-(l-alpha-aminoadipoyl)-l-cysteinyl-d-alanine (ACA) with IPNS has previously been shown to afford acyclic products, in which the substrate cysteinyl residue has undergone a two-electron oxidation. We report X-ray crystal structures for the anaerobic IPNS/Fe(II)/ACG and IPNS/Fe(II)/ACA complexes, both in the absence and presence of the dioxygen analogue nitric oxide. The overall protein structures are very similar to those of the corresponding IPNS/Fe(II)/ACV complexes; however, significant differences are apparent in the vicinity of the active site iron. The structure of the IPNS/Fe(II)/ACG complex reveals that the C-terminal carboxylate of this substrate is oriented toward the active site iron atom, apparently hydrogen-bonded to an additional water ligand at the metal; this is a different binding mode to that observed in the IPNS/Fe(II)/ACV complex. ACA binds to the metal in a manner that is intermediate between those observed for ACV and ACG. The addition of NO to these complexes initiates conformational changes such that both the IPNS/Fe(II)/ACG/NO and IPNS/Fe(II)/ACA/NO structures closely resemble the IPNS/Fe(II)/ACV/NO complex. These results further demonstrate the feasibility of metal-centered rearrangements in catalysis by non-heme iron enzymes and provide insight into the delicate balance between hydrophilic-hydrophobic interactions and steric effects in the IPNS active site. Structural studies on the reaction of isopenicillin N synthase with the truncated substrate analogues delta-(L-alpha-aminoadipoyl)-L-cysteinyl-glycine and delta-(L-alpha-aminoadipoyl)-L-cysteinyl-D-alanine.,Long AJ, Clifton IJ, Roach PL, Baldwin JE, Rutledge PJ, Schofield CJ Biochemistry. 2005 May 3;44(17):6619-28. PMID:15850395 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Isopenicillin N synthase

spinqualitylabelsall models 1w05, resolution 2.46Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image