Penicillin-G acylases

1. An engineered penicillin G acylase (PGA), wherein the PGA comprises an amino acid sequence having at least 95% identity to SEQ ID NO: 4 and at least one of the following amino acid substitutions relative to the reference sequence of SEQ ID NO:32:

residue corresponding to X28 is valine;

residue corresponding to X74 is glycine; and/or

residue corresponding to X547 is glutamine.

2. A composition comprising: (i) a penicillin G of structural formula (I), a 6-amino penicillanic acid of structural formula (II), and/or a phenylacetic acid of structural formula (III); and (ii) an engineered PGA of claim 1 .

3. The engineered PGA of claim 1 , wherein the amino acid sequence further comprises at least one of the following features with respect to the reference sequence of SEQ ID NO:32:

residue corresponding to X24 is a non-polar, aliphatic, or aromatic residue;

residue corresponding to X31 is a cysteine, constrained, aromatic, non-polar, aliphatic, polar, or basic residue;

residue corresponding to X56 is non-polar, aliphatic or polar residue;

residue corresponding to X71 is a cysteine, basic, acidic, aromatic, non-polar, aliphatic or polar residue;

residue corresponding to X697 is an aromatic, non-polar or aliphatic residue; and/or

residue corresponding to X701 is a cysteine, aromatic, constrained, non-polar, or aliphatic residue.

4. The engineered PGA of claim 3 in which the polypeptide amino acid sequence has one or more of the following features with respect to the reference sequence of SEQ ID NO:32:

residue corresponding to X24 is alanine or tyrosine;

residue corresponding to X31 is cysteine, asparagine, threonine, or valine;

residue corresponding to X56 is isoleucine, leucine, or threonine;

residue corresponding to X71 is cysteine, glycine, glutamine, leucine, valine, lysine, arginine, or glutamic acid;

residue corresponding to X697 is phenylalanine, glycine, or leucine; and/or

residue corresponding to X701 is tyrosine or tryptophan.

5. The engineered PGA of claim 1 , wherein the polypeptide comprises an amino acid sequence further comprising at least one of the following features with respect to the reference sequence of SEQ ID NO:32:

residue corresponding to X71 is cysteine, glycine, glutamine, glutamic acid;

residue corresponding to X701 is tyrosine or tryptophan;

residue corresponding to X24 is alanine or tyrosine;

residue corresponding to X56 is isoleucine, leucine, or threonine; and/or

residue corresponding to X697 is phenylalanine, glycine, or leucine.

6. The engineered PGA of claim 1 , wherein the polypeptide comprises an amino acid sequence having further comprising at least one of the following features with respect to the reference sequence of SEQ ID NO:32:

residue corresponding to X31 is phenylalanine, basic, non-polar, aliphatic or polar residue;

residue corresponding to X701 cysteine, phenylalanine, non-polar, aliphatic, or constrained residue;

residue corresponding to X24 is an aromatic, non-polar or aliphatic residue;

residue corresponding to X56 is a non-polar, aliphatic or polar residue;

residue corresponding to X71 is a cysteine, basic, acidic, aromatic, non-polar, aliphatic or polar residue; and/or

residue corresponding to X697 is a non-polar, aliphatic, or aromatic residue.

7. The engineered PGA of claim 1 wherein the polypeptide comprises an amino acid sequence further comprising one or more of the following features with respect to the reference sequence of SEQ ID NO:32:

residue corresponding to X24 is an aromatic, non-polar or aliphatic residue;

residue corresponding to X31 is a cysteine, constrained, aromatic, non-polar, aliphatic, polar, or basic residue;

residue corresponding to X56 is a non-polar, aliphatic or polar residue;

residue corresponding to X71 is a cysteine, basic, acidic, aromatic, non-polar, aliphatic or polar residue;

residue corresponding to X697 is a non-polar, aliphatic, or aromatic residue; and/or

residue corresponding to X701 is a cysteine, phenylalanine, constrained, non-polar, or aliphatic residue.

8. The engineered PGA of claim 1 in which the polypeptide has an improved property as compared to the naturally occurring PGA of Kluyvera citrophila of:

(a) increased thermal stability at 50° C. for 18 hrs;

(b) increased stability to 48% methanol; and/or

(c) increased stability to 30% acetonitrile,

and wherein X28 is valine, X74 is glycine and X547 is glutamine.

9. The engineered PGA of claim 1 wherein the polypeptide comprises an amino acid sequence further comprising one or more of the following features with respect to the reference sequence of SEQ ID NO:32:

residue corresponding to X71 is cysteine, glycine, lysine, or valine; and/or

residue corresponding to X701 is tyrosine.

10. The engineered PGA of claim 1 in which the polypeptide comprises an amino acid sequence selected from SEQ ID NO: 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, 40, 42, 44, 46, 48, 50, 52, 54, 56, 58, 60, 62, 64, 66, 68, 70, 82, 84, 86, 88, 90, 92, 94, 96, 98, 100, 102, 104, 106, 108, 110, 112, 114, 116, 118, 120, 122, 124, 126, 128, 130, 132, 134, 136, 138, 140, 142, 144, 146, 148, 150, 152, 154, 156, 158, 160, 162, 164, 166, 168, 170, 172, 174, 176, and 178.

11. A polynucleotide encoding the engineered PGA of claim 1 .

12. An expression vector comprising the polynucleotide of claim 11 .

13. A host cell comprising the expression vector of claim 12 .

14. A method for cleaving penicillin G of structural formula (I) (“the substrate”) to 6-amino penicillanic acid of structural formula (II) and phenylacetic acid of structural formula (III) (“the products”):

wherein the method comprises:

contacting the penicillin G with an engineered PGA of claim 1 , under reaction conditions suitable for cleaving the substrate to the products.