Chemistry Reference
In-Depth Information
(a)
DH
(ER)
KR
C
KS
AT
C
-MeT
ACP
lovB
OH
O
O
45
OH
O
50
O
O
46
S
(b)
KS
AT
DH
C
-MeT
(ER)
KR
ACP
C
ER
KS
AT
DH
C
-MeT
KR
ACP
lovB
LDKS
ER
HO
lovC
HO
CO
2
H
CO
2
H
OH
HO
HO
OH
O
CO
2
H
CO
2
H
5
OH
OH
AT
O
5
OH
H
H
lovD
10
H
Lovastatin
10
Monacolin J
49
H
47
48
(c)
(ER)
A
KS
AT
DH
C
-MeT
KR
ACP
C
TR
O
N
NH
2
OH
S
S
56
H
O
O
O
O
HO
57
54
Equisetin
KS
AT
DH
C
-MeT
(ER)
KR
ACP
C
A
T
R
H
S
H
N
HO
O
OH
O
58
O
O
OH
N
O
55
Tenellin
OH
O
N
H
59
O
O
OH
O
O
OH
OH
NH
O
H
O
OMe
HO
60
O
O
26
Fusarin C
Figure 6.3
Expression of
lovB
in
A. nidulans
, (a) in the absence and, (b) the presence
of lovC; (c)
lovD
catalyzed acyl transfer of
lovB
diketide (
50
)tomonacolinJ(
49
); (d)
proposed roles of FUSS domains in the biosynthesis of “pre-fusarin” (
60
).
6.6 FUNGAL HR-PKS
The final class of fungal PKS produces complex, highly reduced compounds
such as lovastatin (
10
), T-toxin (
19
), fumonisin B1 (
30
), and squalestatin (
29
).
In all cases, these fungal compounds are produced by iterative Type 1 PKS.
These PKSs have an N-terminal KS domain, followed by AT and DH domains
(Fig. 6.3). In many cases, the DH is followed by a
C
-MeT domain. Some HR
PKSs possess an ER domain, but those that lack it have a roughly equivalent
