## 2 Diversity of LPBSs and NRPSs from _Bacillus_ and _Pseudomonas_
### Bacillus
#### 2.1.1 Surfactin and Lichenysin Synthetases

Table 1: Primary structure of representative lipopeptides produced by _Bacillus_ strains. \begin{table}
\begin{tabular}{l l c c} \hline \hline
**Group/Name** & **Structure** & **Ref. ** \\ \hline
**Visconsin\({}^{\textbf{A}}\)** & & & \\ Visconsin & FA-\(\beta\)-OH-\(\iota\)-Leu-\(\beta\)-Glu-\(\
u\)-\(\tau\)hr-\(\
u\)-Val-\(\iota\)-Leu-\(\beta\)-Ser-\(\iota\)-Leu-\(\beta\)-Ser-\(\iota\)-Ile & [46] \\ Visconsin & FA-\(\beta\)-OH-\(\iota\)-Leu-\(\beta\)-Glu-\(\
u\)-Thr-\(\
u\)-Val-\(\iota\)-Leu-\(\beta\)-Ser-\(\iota\)-Leu-\(\beta\)-Ser-\(\iota\)-Ile & [47] \\ Massetolide & FA-\(\beta\)-OH-\(\iota\)-Leu-\(\beta\)-Glu-\(\
u\)Thr-\(\rho\)-dle-Leu-\(\beta\)-Ser-\(\iota\)-Leu-\(\beta\)-Ser-\(\iota\)-Ile & [48] \\ Pseudophomin & FA-\(\beta\)-OH-\(\iota\)-Leu-\(\beta\)-Glu-\(\
u\)Thr-\(\rho\)-Ile-Leu-\(\beta\)-Ser-\(\iota\)-Leu-\(\beta\)-Ser-\(\iota\)-Ile & [49] \\ Pseudodesmin & FA-\(\beta\)-OH-\(\iota\)-Leu-\(\beta\)-Glu-\(\
u\)Thr-\(\rho\)-Val-\(\iota\)-Leu-\(\beta\)-Ser-\(\iota\)-Leu-\(\beta\)-Ser-\(\iota\)-Ile & [50] \\
**Syringomycin\({}^{\textbf{B}}\)** & & \\ Syringomycin & FA-\(\beta\)-OH-\(\iota\)-Ser-D-Ser-D-D-D-D-D-A-\(\iota\)-Phe-\(\iota  
\begin{table}
\begin{tabular}{l l l c} \hline \hline
**Springopeptin\({}^{\rm A}\)** & & & \\ SP22 & FA-\(\beta\)-OH-Dh-Pro-Val-Val-Ala-Ala-Val  
The biosynthetic gene clusters of surfactin [69] and lichenysin [32], namely _srfA_ and _lic_, are highly homologous and extend over 25 kb (Figure 1). They contain four open reading frames (ORFs), _srfA-A/licA_, _srfA-B/licB_, _srfA-C/licC_, and _srfA-Te/lic-Te_. The amino acid sequences of the first three ORFs are homologous to other NRPSs whereas the last ORF encodes a putative type II Te. SrfA-A/B/C and LicA/B/C are composed of three, three, and one module(s), and each ORF can be further subdivided into functional domains. SrfA and Lic bear six typical C-domains that catalyze  
Figure 1: Multidomain organization of the gene clusters encoding NRPSs from _Bacillus_ (**A**) and _Pseudomonas_ (**B**). amide bond formation. An additional C-domain, the _N_-acyl domain, is located at the _N_-terminal domain of the first module, suggesting that the first amino acid is initially _N_-acylated with a \(\beta\)-hydroxy fatty acid in this domain [32, 70]. Recently, [PERSON] and coworkers (2010) have shown that the _N_-acyl domain in SrfA transfers CoA-activated 3-hydroxy fatty acid to the first T-domain where the _N_-terminal Glu is bound [71]. SrfA and Lic contain the conventional E-domains essential for the transformation of L-amino acids to d-amino acids and a _C_-terminal type I Te-domain that releases the final product. In addition to the _C_-terminal type I Te-domain, SrfA and Lic have an external type II Te protein, SrfA-Te/LicTe. A decreased production of surfactin (84%) is observed in the SrfA-Te mutant [72]. The external type II Te is involved in regenerating misprimed T-domains by removing short acyl chains from the 4'-phosphopantetheine cofactors and thereby regenerates functional NRPSs [73]. Moreover, a study has suggested that the type II Te also hydrolyzes incorrectly loaded amino acids that are not processed by the nonribosomal machinery [74]. SrfA-Te also functions as the thioesterase/acyltransferase that supports and stimulates the formation of \(\beta\)-hydroxymyristoyl-glutamate, an initiation substrate of surfactin synthesis [75, 76].