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| Enzyme Name | | Swiss-prot | KEGG |
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| P12256 |
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| Protein name | Penicillin acylase | penicillin amidasepenicillin acylasebenzylpenicillin acylasenovozym 217semacylasealpha-acylamino-beta-lactam acylhydrolaseampicillin acylase |
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| Synonyms | EC 3.5.1.11Penicillin V amidasePVA |
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| KEGG pathways | | MAP code | Pathways |
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| MAP00311 | Penicillin and cephalosporin biosynthesis |
| Swiss-prot:Accession Number | P12256 |
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| Entry name | PAC_BACSH |
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| Activity | Penicillin + H(2)O = a carboxylate + 6- aminopenicillanate. |
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| Subunit | Homotetramer. |
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| Subcellular location |
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| Cofactor |
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| Substrates | Products |
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| KEGG-id | C00395 | C00001 | C00060 | C02954 |
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| Compound | Penicillin | H2O | Carboxylate | 6-Aminopenicillanate |
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| Type | carboxyl group,peptide/protein,sulfide group | H2O | carboxyl group | amide group,amine group,carboxyl group,sulfide group |
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| 2pvaA |  | Unbound |
| Unbound | Unbound |
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| 2pvaB |  | Unbound |
| Unbound | Unbound |
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| 2pvaC |  | Unbound |
| Unbound | Unbound |
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| 2pvaD |  | Unbound |
| Unbound | Unbound |
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| 3pvaA |  | Unbound |
| Unbound | Unbound |
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| 3pvaB |  | Unbound |
| Unbound | Unbound |
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| 3pvaC |  | Unbound |
| Unbound | Unbound |
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| 3pvaD |  | Unbound |
| Unbound | Unbound |
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| 3pvaE |  | Unbound |
| Unbound | Unbound |
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| 3pvaF |  | Unbound |
| Unbound | Unbound |
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| 3pvaG |  | Unbound |
| Unbound | Unbound |
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| 3pvaH |  | Unbound |
| Unbound | Unbound |
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| References for Catalytic Mechanism | | References | Sections | No. of steps in catalysis |
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| [1] | Fig.3 | 5 | | [3] | p.239 |
| | [4] | p.414 |
| | [6] | Fig.2 | 3 | | [7] | p.146-147 |
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| references | | [1] |
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| Comments | Penicillin G acylase (homologous enzyme) |
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| PubMed ID | 7816145 |
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| Journal | Nature |
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| Year | 1995 |
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| Volume | 373 |
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| Pages | 264-8 |
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| Authors | Duggleby HJ, Tolley SP, Hill CP, Dodson EJ, Dodson G, Moody PC |
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| Title | Penicillin acylase has a single-amino-acid catalytic centre. |
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| [2] |
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| Comments | Penicillin G acylase (homologous enzyme) |
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| PubMed ID | 7477383 |
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| Journal | Nature |
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| Year | 1995 |
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| Volume | 378 |
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| Pages | 416-9 |
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| Authors | Brannigan JA, Dodson G, Duggleby HJ, Moody PC, Smith JL, Tomchick DR, Murzin AG |
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| Title | A protein catalytic framework with an N-terminal nucleophile is capable of self-activation. |
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| [3] |
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| Comments | Penicillin G acylase (homologous enzyme) |
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| PubMed ID | 9931321 |
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| Journal | Biochem J |
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| Year | 1999 |
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| Volume | 338 |
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| Pages | 235-9 |
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| Authors | Morillas M, Goble ML, Virden R |
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| Title | The kinetics of acylation and deacylation of penicillin acylase from Escherichia coli ATCC 11105: evidence for lowered pKa values of groups near the catalytic centre. |
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| [4] |
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| Comments | X-ray crystallography |
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| PubMed ID | 10331865 |
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| Journal | Nat Struct Biol |
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| Year | 1999 |
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| Volume | 6 |
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| Pages | 414-416 |
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| Authors | Suresh CG, Pundle AV, SivaRaman H, Rao KN, Brannigan JA, McVey CE, Verma CS, Dauter Z, Dodson EJ, Dodson GG |
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| Title | Penicillin V acylase crystal structure reveals new Ntn-hydrolase family members. |
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| Related PDB | 2pva,3pva |
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| [5] |
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| Comments | Penicillin G acylase (homologous enzyme) |
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| PubMed ID | 10993730 |
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| Journal | J Mol Biol |
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| Year | 2000 |
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| Volume | 302 |
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| Pages | 887-98 |
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| Authors | Hewitt L, Kasche V, Lummer K, Lewis RJ, Murshudov GN, Verma CS, Dodson GG, Wilson KS |
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| Title | Structure of a slow processing precursor penicillin acylase from Escherichia coli reveals the linker peptide blocking the active-site cleft. |
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| [6] |
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| Comments | X-ray crystallography, catalysis; Penicillin G acylase (homologous enzyme) |
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| PubMed ID | 11239085 |
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| Journal | Protein Eng |
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| Year | 2000 |
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| Volume | 13 |
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| Pages | 857-863 |
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| Authors | Alkema WB, Hensgens CM, Kroezinga EH, de Vries E, Floris R, van der Laan JM, Dijkstra BW, Janssen DB |
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| Title | Characterization of the beta-lactam binding site of penicillin acylase of Escherichia coli by structural and site-directed mutagenesis studies. |
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| [7] |
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| Comments | X-ray crystallography (1.3 Angstroms), catalysis; Penicillin G acylase (homologous enzyme) |
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| PubMed ID | 11601852 |
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| Journal | J Mol Biol |
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| Year | 2001 |
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| Volume | 313 |
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| Pages | 139-150 |
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| Authors | McVey CE, Walsh MA, Dodson GG, Wilson KS, Brannigan JA |
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| Title | Crystal structures of penicillin acylase enzyme-substrate complexes: structural insights into the catalytic mechanism. |
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| comments | This enzyme belongs to N-terminal nucleophile (Ntn) hydrolase family, of which sidechain of the N-terminal residue acts as nucleophile, assisted by its own alpha-amino group. The paper [1] proposed the catalytic mechanism of the homologous enzyme, penicillin G acylase, whose nucleophilic residue is serine instead of cysteine. (1) The alpha-amino group enhances the nucleophilicity of the sidechain of the N-terminal residue, through the bridging water between them. (2) The sidechain of Cys1 makes a nucleophilic attack on the acyl carbon of penicillin, forming an oxyanion tetrahedral, stabilized by the oxyanion hole composed of mainchain amides and sidechain of Asn175. Here, the alpha-amino group protonates the leaving amine group through a water. (3) This tetrahedral intermediate will then collapse to form an acyl enzyme and release the free 6-aminopenicillanic acid. (4) The acyl enzyme will be attacked by water to form a second tetrahedral intermediate, stabilized by the same oxyanion hole, which can in turn collapse to release the free phenylacetic acid. In contrast, the literature [7] suggested that the catalytic mechanism proceeds via direct nucleophilic attack of the nucleophilic residue on the scissile amide and not as via the bridging water molecule acting as a "virtual" base. According to the paper [3], the residue corresponding to Arg228 in its homologue, penicillin G acylase, seems to be important for catalysis, orienting the N-terminal catalytic residue and contributing to a decrease in the pKa of alpha-amino group. The literature on this enzyme [4] reported that the oxyanion hole consists of the sidechain of Asn175 and NH of Tyr82, whilst Arg228, Asp20 and Asn175 are critical for positioning the lone pair of the unprotonated N-terminal alpha-amino group. This might lead to the decrease in the pKa of the alpha-amino group.
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| created | updated |
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| 2002-09-04 | 2009-02-26 |
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