bacitracin synthetase and related proteins. This family of the adenylation (A) domain of nonribosomal peptide synthases (NRPS) includes bacitracin synthetases 1, 2, and 3 (BA1, also known as ATP-dependent cysteine adenylase or cysteine activase, BA2, also known as ATP-dependent lysine adenylase or lysine activase, and BA3, also known as ATP-dependent isoleucine adenylase or isoleucine activase) in Bacilli. Bacitracin is a mixture of related cyclic peptides used as a polypeptide antibiotic. This family also includes gramicidin synthetase 1 involved in synthesis of the cyclic peptide antibiotic gramicidin S via activation of phenylalanine. NRPSs are large multifunctional enzymes which synthesize many therapeutically useful peptides in bacteria and fungi via a template-directed, nucleic acid independent nonribosomal mechanism. These natural products include antibiotics, immunosuppressants, plant and animal toxins, and enzyme inhibitors. NRPS has a distinct modular structure in which each module is responsible for the recognition, activation, and in some cases, modification of a single amino acid residue of the final peptide product. The modules can be subdivided into domains that catalyze specific biochemical reactions.

LCL-type Condensation (C) domain of non-ribosomal peptide synthetases(NRPSs) and similar domains including the C-domain of SgcC5, a free-standing NRPS with both ester- and amide- bond forming activity. LCL-type Condensation (C) domains catalyze peptide bond formation between two L-amino acids, ((L)C(L)). C-domains of NRPSs catalyze peptide bond formation within (usually) large multi-modular enzymatic complexes. NRPS can use a large variety of acyl monomers (approximately 500 different possible monomer substrates as opposed to the 20 standard amino acids in ribosomal protein synthesis) to construct bioactive secondary metabolites of 2 to 18 units long (with various activities such as antibiotic, antifungal, antitumor and immunosuppression). In addition to the LCL-type, there are various subtypes of C-domains such as the DCL-type which links an L-amino acid to the D-amino acid at the end of a growing peptide, starter C-domains which acylate the first amino acid with a beta-hydroxy carboxylic acid, and heterocyclization (Cyc) domains which catalyze both peptide bond formation and cyclization of Cys, Ser, or Thr residues. Typically, an NRPS module consists of an adenylation domain, a peptidyl carrier protein (PCP) domain (also known as thiolation (T) domain) and a C-domain. NRPS modules may also include specialized domains such as the terminal-module thioesterase (Te) domain that releases the product via hydrolysis or macrocyclization and any of various C-domain family members such as the epimerization (E) domain, the ester-bond forming C-domain, dual E/C (epimerization and condensation) domains, and the X-domain. Streptomyces globisporus SgcC5 is a free-standing NRPS condensation enzyme (rather than a modular NRPS), which catalyzes the condensation between the SgcC2-tethered (S)-3-chloro-5-hydroxy-beta-tyrosine and (R)-1phenyl-1,2-ethanediol, forming an ester bond, during the synthesis of the chromoprotein enediyne antitumor antibiotic C-1027. It has some acceptor substrate promiscuity as it has been shown to also catalyze the formation of an amide bond between SgcC2-tethered (S)-3-chloro-5-hydroxy-beta-tyrosine and a mimic of the enediyne core acceptor substrate having an amine at its C-2 position. C-domains typically have a conserved HHxxxD motif at the active site; mutations in this motif can abolish or diminish condensation activity. An HHxx[SAG]DGxSx(6)[ED] motif is characteristic of LCL-type C-domains.

LCL-type Condensation (C) domain of non-ribosomal peptide synthetases(NRPSs) and similar domains including the C-domain of SgcC5, a free-standing NRPS with both ester- and amide- bond forming activity. LCL-type Condensation (C) domains catalyze peptide bond formation between two L-amino acids, ((L)C(L)). C-domains of NRPSs catalyze peptide bond formation within (usually) large multi-modular enzymatic complexes. NRPS can use a large variety of acyl monomers (approximately 500 different possible monomer substrates as opposed to the 20 standard amino acids in ribosomal protein synthesis) to construct bioactive secondary metabolites of 2 to 18 units long (with various activities such as antibiotic, antifungal, antitumor and immunosuppression). In addition to the LCL-type, there are various subtypes of C-domains such as the DCL-type which links an L-amino acid to the D-amino acid at the end of a growing peptide, starter C-domains which acylate the first amino acid with a beta-hydroxy carboxylic acid, and heterocyclization (Cyc) domains which catalyze both peptide bond formation and cyclization of Cys, Ser, or Thr residues. Typically, an NRPS module consists of an adenylation domain, a peptidyl carrier protein (PCP) domain (also known as thiolation (T) domain) and a C-domain. NRPS modules may also include specialized domains such as the terminal-module thioesterase (Te) domain that releases the product via hydrolysis or macrocyclization and any of various C-domain family members such as the epimerization (E) domain, the ester-bond forming C-domain, dual E/C (epimerization and condensation) domains, and the X-domain. Streptomyces globisporus SgcC5 is a free-standing NRPS condensation enzyme (rather than a modular NRPS), which catalyzes the condensation between the SgcC2-tethered (S)-3-chloro-5-hydroxy-beta-tyrosine and (R)-1phenyl-1,2-ethanediol, forming an ester bond, during the synthesis of the chromoprotein enediyne antitumor antibiotic C-1027. It has some acceptor substrate promiscuity as it has been shown to also catalyze the formation of an amide bond between SgcC2-tethered (S)-3-chloro-5-hydroxy-beta-tyrosine and a mimic of the enediyne core acceptor substrate having an amine at its C-2 position. C-domains typically have a conserved HHxxxD motif at the active site; mutations in this motif can abolish or diminish condensation activity. An HHxx[SAG]DGxSx(6)[ED] motif is characteristic of LCL-type C-domains.

LCL-type Condensation (C) domain of non-ribosomal peptide synthetases(NRPSs) and similar domains including the C-domain of SgcC5, a free-standing NRPS with both ester- and amide- bond forming activity. LCL-type Condensation (C) domains catalyze peptide bond formation between two L-amino acids, ((L)C(L)). C-domains of NRPSs catalyze peptide bond formation within (usually) large multi-modular enzymatic complexes. NRPS can use a large variety of acyl monomers (approximately 500 different possible monomer substrates as opposed to the 20 standard amino acids in ribosomal protein synthesis) to construct bioactive secondary metabolites of 2 to 18 units long (with various activities such as antibiotic, antifungal, antitumor and immunosuppression). In addition to the LCL-type, there are various subtypes of C-domains such as the DCL-type which links an L-amino acid to the D-amino acid at the end of a growing peptide, starter C-domains which acylate the first amino acid with a beta-hydroxy carboxylic acid, and heterocyclization (Cyc) domains which catalyze both peptide bond formation and cyclization of Cys, Ser, or Thr residues. Typically, an NRPS module consists of an adenylation domain, a peptidyl carrier protein (PCP) domain (also known as thiolation (T) domain) and a C-domain. NRPS modules may also include specialized domains such as the terminal-module thioesterase (Te) domain that releases the product via hydrolysis or macrocyclization and any of various C-domain family members such as the epimerization (E) domain, the ester-bond forming C-domain, dual E/C (epimerization and condensation) domains, and the X-domain. Streptomyces globisporus SgcC5 is a free-standing NRPS condensation enzyme (rather than a modular NRPS), which catalyzes the condensation between the SgcC2-tethered (S)-3-chloro-5-hydroxy-beta-tyrosine and (R)-1phenyl-1,2-ethanediol, forming an ester bond, during the synthesis of the chromoprotein enediyne antitumor antibiotic C-1027. It has some acceptor substrate promiscuity as it has been shown to also catalyze the formation of an amide bond between SgcC2-tethered (S)-3-chloro-5-hydroxy-beta-tyrosine and a mimic of the enediyne core acceptor substrate having an amine at its C-2 position. C-domains typically have a conserved HHxxxD motif at the active site; mutations in this motif can abolish or diminish condensation activity. An HHxx[SAG]DGxSx(6)[ED] motif is characteristic of LCL-type C-domains.

bacitracin synthetase and related proteins. This family of the adenylation (A) domain of nonribosomal peptide synthases (NRPS) includes bacitracin synthetases 1, 2, and 3 (BA1, also known as ATP-dependent cysteine adenylase or cysteine activase, BA2, also known as ATP-dependent lysine adenylase or lysine activase, and BA3, also known as ATP-dependent isoleucine adenylase or isoleucine activase) in Bacilli. Bacitracin is a mixture of related cyclic peptides used as a polypeptide antibiotic. This family also includes gramicidin synthetase 1 involved in synthesis of the cyclic peptide antibiotic gramicidin S via activation of phenylalanine. NRPSs are large multifunctional enzymes which synthesize many therapeutically useful peptides in bacteria and fungi via a template-directed, nucleic acid independent nonribosomal mechanism. These natural products include antibiotics, immunosuppressants, plant and animal toxins, and enzyme inhibitors. NRPS has a distinct modular structure in which each module is responsible for the recognition, activation, and in some cases, modification of a single amino acid residue of the final peptide product. The modules can be subdivided into domains that catalyze specific biochemical reactions.

Crystalstructure of a 5-domain construct of LgrA in the substrate donation state [Brevibacillus parabrevis],6MG0_A Crystal structure of a 5-domain construct of LgrA in the thiolation state [Brevibacillus parabrevis],6MG0_B Crystal structure of a 5-domain construct of LgrA in the thiolation state [Brevibacillus parabrevis]

Crystalstructure of dimodular LgrA in a condensation state [Brevibacillus parabrevis],6MFZ_B Crystal structure of dimodular LgrA in a condensation state [Brevibacillus parabrevis]

Crystalstructure of a cross-module fragment from the dimodular NRPS DhbF [Geobacillus sp. Y4.1MC1]

Thestructure of condensation and adenylation domains of teixobactin-producing nonribosomal peptide synthetase Txo2 serine module [Eleftheria terrae],6P1J_B The structure of condensation and adenylation domains of teixobactin-producing nonribosomal peptide synthetase Txo2 serine module [Eleftheria terrae]

Crystalstructure of a 4-domain construct of LgrA in the substrate donation state [Brevibacillus parabrevis]

Plipastatin synthase subunit A OS=Bacillus subtilis (strain 168) OX=224308 GN=ppsA PE=1 SV=2

Plipastatin synthase subunit D OS=Bacillus subtilis (strain 168) OX=224308 GN=ppsD PE=1 SV=2

Plipastatin synthase subunit C OS=Bacillus subtilis (strain 168) OX=224308 GN=ppsC PE=1 SV=2

Plipastatin synthase subunit B OS=Bacillus subtilis (strain 168) OX=224308 GN=ppsB PE=1 SV=1

Surfactin synthase subunit 2 OS=Bacillus subtilis (strain 168) OX=224308 GN=srfAB PE=1 SV=3