᳜≀䝫䝸䜿䝍䜲䝗ྜᡂ㓝⣲䛾ゐ፹ᶵ⬟䛾ᣑᙇ䛸㠀ኳ↛ᆺྜ≀⩌䛾ฟ
ᐩᒣᏛ₎་⸆Ꮫ⥲ྜ◊✲ᡤ ኳ↛≀Ꮫศ㔝
᳃⏣ὒ⾜
㸯㸬ࡣࡌࡵ
་⸆㈨※ࡋ࡚ࡶ㔜せ࡞ኳ↛≀ࡢᇶᮏ㦵᱁ࢆᵓ⠏ࡍࡿḟ௦ㅰ㓝⣲ࡢ୰ࡣ㸪άᛶ㒊ࡢᚤጁ࡞ᵓ㐀 ࡢ㐪࠸ࡼࡾᇶ㉁≉␗ᛶࡸᛂᵝᘧࡀࡁࡃኚࡍࡿࡶࡢࡀ࠶ࡾ㸪ࡇࢀࡀኳ↛≀ࡢከᵝᛶࢆ⏕ࡳฟࡍ
ࡁ࡞せᅉ࡞ࡗ࡚࠸ࡿ㸬ࡲࡓ㸪୍⯡㸪㓝⣲ࡢᇶ㉁≉␗ᛶࡣཝᐦ࡛⮬⏤ᗘࡀప࠸ࡶࡢࡉࢀ࡚࠸ࡿࡀ㸪 ࡇࢀࡽࡢ୰ࡣᐶᐜ࡞ᇶ㉁≉␗ᛶࡸ₯ᅾⓗゐ፹⬟ຊࢆ᭷ࡍࡿࡶࡢࡶ࠶ࡿ㸬ᡃࠎࡣ㸪ḟ௦ㅰ⏘≀ࡢᵓ㐀 ከᵝᛶࡢฟ㛵ࢃࡿ㝈ࡽࢀࡓᩘࡢ
C-C⤖ྜᙧᡂ⬟ࢆ᭷ࡍࡿ⏕ྜᡂ㓝⣲ࡢ⏕≀᭷ᶵ⛉Ꮫᵓ㐀⏕≀Ꮫ ࡢ」ྜⓗ᳨ウࡀ㸪de novo ྜᡂࡶᛂ⏝ྍ⬟࡞᪂ࡓ࡞⏕యゐ፹ࡢ㛤ᣅ↓㝈ࡢศᏊከᵝᛶࡢฟ⤖ᐇ ࡍࡿࡇࢆಙࡌ㸪ḟ௦ㅰ㓝⣲ࡢᶵ⬟ゎᯒ᪂つྜ≀⩌ࡢ㓝⣲ྜᡂἲࡢ㛤ᣅྲྀࡾ⤌ࢇ࡛࠸ࡿ㸬 ᮏ✏࡛ࡣ㸪ࣇࣛ࣎ࣀࢻࡸࢫࢳࣝ࣋ࣥ➼㸪་⸆㈨※ࡋ࡚ࡶ㔜せ࡞᳜≀࣏ࣜࣇ࢙ࣀ࣮ࣝࡢᇶᮏ㦵᱁ࢆ
ᵓ⠏ࡍࡿ᳜≀⏤᮶Ϫᆺ࣏ࣜࢣࢱࢻྜᡂ㓝⣲㸦PKS㸧ࢆྲྀࡾୖࡆࡿ㸬ࡇࢀࡽࡣ㸪ᛂࡢ❧యᏛࡀཝᐦ
ไᚚࡉࢀࡓࠕ⢭ᕦ࡞㓝⣲ࢩࢫࢸ࣒࡛ࠖ࠶ࡿࡣゝ࠸㞴ࡃ㸪ࡴࡋࢁ༢⣧࡞ࢩࣝᇶ㌿⛣ࡢ⧞ࡾ㏉ࡋࡼ
ࡿࠕⅣ⣲㙐ఙ㛗࣐ࢩࣥࠖᤊ࠼ࡿࡇࡀ࡛ࡁࡿ
1,2)㸬Cys-His-Asn ࡽ࡞ࡿάᛶ୰ᚰゐ፹ṧᇶࡣ㸪࡚ࡢ Ϫᆺ
PKS࠾࠸࡚እ࡞ࡃಖᏑࡉࢀ࡚࠾ࡾ㸪ྠ୍ࡢࢣ࣑ࢫࢺ࣮࡛ࣜ㸪࣐ࣟࢽࣝ
CoAࡢ⬺Ⅳ㓟ࢆకࡗࡓ
Claisen
⦰ྜࡢ⧞ࡾ㏉ࡋࡼࡿⅣ⣲㙐ఙ㛗ᛂࡀ㐍⾜ࡍࡿ㸬ᡃࠎࡣ㸪Ϫᆺ
PKSࡢ㓝⣲ᕤᏛⓗ᳨ウࡀ⸆
ࢩ࣮ࢻࡶ࡞ࡾᚓࡿ↓㝈ࡢ㦵᱁ከᵝᛶࢆ⏕ࡳฟࡋᚓࡿࡇࢆ㸪Ϫᆺ
PKSࡢᇶ㉁ᵓ㐀ࣞࣥࢪࢆຍ࠼㸪
ࡘ㸪Ϫᆺ
PKSࡢ㓝⣲ゐ፹ᶵ⬟ࢆᨵኚࡋ࡚Ϫᆺ
PKSࡀゐ፹ࡍࡿ࣐ࣟࢽࣝ
CoAࡢ⦰ྜᅇᩘࢆᣑᙇࡍࡿࡇ
ࡼࡗ࡚ᐇドࡋ࡚ࡁࡓ㸬ᅇࡣ㸪Ϫᆺ
PKSࡢ
X⥺⤖ᬗᵓ㐀ゎᯒ㸪ࡑࢀࢆᇶ┙ࡋࡓྜ⌮ⓗ࡞㓝⣲
ゐ፹ᶵ⬟ࡢᣑᙇࡼࡿ᪂つྜ≀ࡢฟࡘ࠸࡚⤂ࡍࡿ㸬
㸰㸬᳜≀࣏ࣜࣇ࢙ࣀ࣮ࣝࡢᇶᮏ㦵᱁ࢆᵓ⠏ࡍࡿϪᆺ3.6ࡘ࠸࡚
᳜≀⏤᮶Ϫᆺ
PKSࡣ㸪ศᏊ㔞⣙㸲ࡢࢧࣈࣘࢽࢵࢺࡽ࡞ࡿ㸪ࢣࢺྜᡂ㓝⣲㸦KS㸧ࡢࡳ࡛ᵓᡂࡉࢀ
ࡓ࣍ࣔࢲ࣐࣮㓝⣲࡛࠶ࡾ㸪ࣇࣛ࣎ࣀࢻࡸࣞࢫ࣋ࣛࢺ࣮ࣟࣝ➼㸪᳜≀ࡀ⏕⏘ࡍࡿ࣏ࣜࣇ࢙ࣀ࣮ࣝ㢮ࡢ ᇶᮏ㦵᱁ࢆᵓ⠏ࡍࡿ㓝⣲⩌࡛࠶ࡿ
1,2)㸬࠼ࡤ㸪᳜≀ᬑ㐢ⓗᏑᅾࡍࡿࣇࣛ࣎ࣀࢻࡢ㦵᱁ࢆᵓ⠏ࡍ
ࡿ࢝ࣝࢥࣥྜᡂ㓝⣲㸦CHS㸧ࡣ㸪
1ศᏊࡢࢡ࣐ࣟࣝ
CoAࢆ㛤ጞᇶ㉁ࡋ࡚㸪3 ศᏊࡢ࣐ࣟࢽࣝ
CoA
⏤᮶ࡍࡿ
C2༢ࢆ㡰ḟ⦰ྜࡢᚋ㸪ࢡࣛࢮࣥᆺࡢ㛢⎔ᛂࡀ㐍⾜ࡋ࡚㸪ⰾ㤶⎔ࢆᙧᡂࡋ㸪ࢼࣜࣥࢤࢽ
ࣥ࢝ࣝࢥࣥࢆ⏕ᡂࡍࡿ㸦ᅗ㸯㸧㸬ࡇࢀ௨እࡶ㸪ࣈࢻ࢘➼ࡢ㝈ࡽࢀࡓ᳜≀ศᕸࡍࡿࢫࢳࣝ࣋ࣥྜᡂ㓝
⣲㸦STS㸧ࡸ࣍ࢵࣉࡢࣂࣞࣟࣇ࢙ࣀࣥྜᡂ㓝⣲㸦VPS㸧➼㸪ᵝࠎ࡞ᶵ⬟ࢆ᭷ࡍࡿϪᆺ
PKSࡀ▱ࡽࢀ࡚࠸
ࡿ㸦ᅗ㸯㸧㸬ࡇࡢࡼ࠺࡞ศᏊከᵝᛶࢆ⏕ࡳฟࡍせᅉࡋ࡚㸪㓝⣲ᛂࡢ㛤ጞᇶ㉁㸪࣏ࣜࢣࢱࢻ㙐㛗ࢆ
Ỵᐃࡍࡿ࣐ࣟࢽࣝ
CoAࡢ⦰ྜᅇᩘ㸪ࡑࡋ࡚᭱⤊ⓗ࡞㛢⎔ᛂᵝᘧࡢ㐪࠸ࡀᣲࡆࡽࢀࡿ㸬
H2O CoAS
O
OH OH
EnzS O O
CO2 O
O O
SEnz
O
1
x+
1
6
CoAS O
OH
3
x+
CoAS O
OH
3
x+
H2O
CO2
OH
OH HO OH
O O
O 1SEnz
2 7
O
CoAS
O +
3
xCHS
OHO
OH OH
HO
OH
O O
O SEnz
O
1
6
O OH HO
OH
CoAS
O +
2
x 15
O O OH CoAS
O O OH CoAS
O O OH CoAS
O O OH CoAS
O O OH CoAS
O
OH O
STS
VPS
OH
O O
O O
2-PS
SEnzBAS
ᅗ㸯 ᳜≀࣏ࣜࣇ࢙ࣀ࣮ࣝ㢮ࡢ⏕ྜᡂ㛵ࢃࡿ௦⾲ⓗ࡞Ϫᆺ
3.6CHS㸹࢝ࣝࢥࣥྜᡂ㓝⣲㸪STS㸹ࢫࢳࣝ࣋ࣥྜᡂ㓝⣲㸪VPS㸹ࣂࣞࣟࣇ࢙ࣀࣥྜᡂ㓝⣲㸪2-PS㸹2-࣓ࢳ
ࣝࣃࣟࣥྜᡂ㓝⣲㸪BAS㸹࣋ࣥࢨࣝࢭࢺࣥྜᡂ㓝⣲㸬
Ϫᆺ
PKSࡢ㓝⣲ᛂࡣ㸪༢㔞యࡑࢀࡒࢀࡢࡰ୰ኸ㒊୍ࡘࡎࡘᏑᅾࡍࡿάᛶ୰ᚰ࢟ࣕࣅࢸ㸪
ࢩࣝᇶࡀྲྀࡾ㎸ࡲࢀࡿࡇࡼࡗ࡚㛤ጞࡍࡿ㸬ࡇࢀࡼࡾ㸪㞄᥋ࡍࡿ
HisࡢỈ⣲⤖ྜࡼࡾᏳᐃ
ࡉࢀࡓάᛶ୰ᚰ
Cysࡢࢳ࣮࢜ࣞࢺࢽ࢜ࣥࡀ㸪㛤ጞᇶ㉁ࡢ࢝ࣝ࣎ࢽࣝⅣ⣲ࢆồ᰾ᨷᧁࡍࡿ㸬ḟ࠸࡛ࡇࡢ
Cysṧᇶࢆ㉳Ⅼࡋ࡚㸪ఙ㛗ᇶ㉁࣐ࣟࢽࣝ
CoAࡢ⬺Ⅳ㓟ࢆకࡗࡓࢩࣝᇶࡢ㌿⛣ࢆ⧞ࡾ㏉ࡋ㸪༶ࡕ㸪Ⅳ
⣲㙐ఙ㛗ࡢᗘ࠸ࡗࡓࢇᙧᡂࡉࢀࡓࢳ࢚࢜ࢫࢸࣝ⤖ྜࡀ㛤ࡋ࡚㸪ࡑࡇ᪂ࡓ࡞
C2༢ࡢᤄධࢆ⧞ࡾ
㏉ࡋ㸪᭱ᚋ
β-࣏ࣜࢣࢺ࣓ࢳࣞࣥ୰㛫యࡀࢡࣛࢮࣥ࠶ࡿ࠸ࡣࣝࢻ࣮ࣝᆺࡢ⦰ྜࡼࡾ㛢⎔ࡋ࡚㸪㓝⣲ᛂࢆ⤊ࡍࡿ㸬ࡇࡢ㛫㸪His
Asnṧᇶࡣ㸪࢜࢟ࢩࢽ࣭࣮࢜ࣥ࣍ࣝࢆᙧᡂࡋ㸪࣐ࢼࢫⲴ㟁ࡋ ࡓ㑄⛣≧ែ୰㛫యࢆᏳᐃࡍࡿࡇࡼࡾ㸪࣐ࣟࢽࣝ
CoAࡢ⬺Ⅳ㓟ࡑࡢ⤖ᯝ⏕ࡌࡿ࢚ࣀ࣮ࣛࢺࢽ
࢜ࣥࡢồ᰾ᨷᧁࢆಁ㐍ࡍࡿ㸦ᅗ㸰㸧㸬
ࡇࡢ
Cys-His-Asnࡽ࡞ࡿάᛶ୰ᚰゐ፹ṧᇶࡣ㸪ᶵ⬟ࡢ␗࡞ࡿ࡚ࡢϪᆺ
PKS࠾࠸࡚ಖᏑࡉࢀ࡚࠾
ࡾ㸪ྠ୍ࡢᛂᶵᵓ࡛࣏ࣜࢣࢱࢻ㙐ఙ㛗ᛂࡀ㐍⾜ࡍࡿࡶࡢ⪃࠼ࡽࢀ࡚࠸ࡿ㸬᪥࡛ࡣ㸪
CHSࢆࡣ
ࡌࡵࡋ࡚㸪᪤
12✀㢮ࡢ㓝⣲ࡢ
X⥺⤖ᬗᵓ㐀ゎᯒࡀ࡞ࡉࢀ࡚࠾ࡾ㸪࠸ࡎࢀࡢ㓝⣲ࡶ㸪ࢱࣥࣃࢡ㉁
యࡋ࡚ࡣ㸪ࡰྠ୍ࡢ❧యᵓ㐀ࢆඹ᭷ࡍࡿࡇ㸪άᛶ୰ᚰ࢟ࣕࣅࢸࡣࢱࣥࣃࢡ㉁ᵓ㐀ࡢ୰ᚰ㒊
⨨ࡋ࡚࠾ࡾ㸪ࡇࢀ
CoA࢚ࢫࢸࣝࡢᇶ㉁⤖ྜࢺࣥࢿࣝࡀࢱࣥࣃࢡ⾲㠃ࡽ㏻ࡌ࡚࠸ࡿࡇ㸪άᛶ୰ᚰ
ゐ፹ṧᇶ
Cys-His-Asnࡀάᛶ୰ᚰ࢟ࣕࣅࢸᇶ㉁⤖ྜࢺࣥࢿࣝࡢቃ⏺⨨ࡋ࡚࠸ࡿࡇ➼ࡀ᫂ࡽ
࡞ࡗ࡚࠸ࡿ
1-5)㸬ࡲࡓ㸪ࡇࢀࡲ࡛ࡢゎᯒࡼࡾ㸪Ϫᆺ
PKSࡢᶵ⬟ከᵝᛶࡣ㸪άᛶ୰ᚰ࢟ࣕࣅࢸࡢ
ࡁࡉᙧ≧ࡼࡗ࡚ࡋ࡚Ỵᐃࡉࢀࡿࡇࡀ♧၀ࡉࢀ࡚࠸ࡿ㸬୍᪉㸪Ϫᆺ
PKSࡣ࠸
50%௨ୖࡢ࣑ࣀ㓟㓄ิ┦ྠᛶࢆ♧ࡋ㸪ࡋࡶάᛶ㒊ࡢᚤጁ࡞ᵓ㐀ࡢ㐪࠸ࡼࡾ㸪ࡑࡢᛂ≉␗ᛶࡸ⏕ᡂ≀≉␗
ᛶࡀࡁࡃኚࡍࡿࡓࡵ㸦ྠ୍ࡢ࣑ࣀ㓟ṧᇶ࡛ࢥ࣮ࢻࡉࢀ࡚࠸ࡓࡋ࡚ࡶ㸪✵㛫ⓗ࡞㓄⨨ࡸ㓄ྥ㐪
࠸ࡀ⏕ࡌ࡚࠸ࡿሙྜࡀ࠶ࡿ㸟㸧㸪࣑ࣀ㓟㓄ิࡽᶵ⬟ࢆண ࡍࡿࡇࡣྍ⬟࡛࠶ࡿ㸬
N HN + H
C164 SH
N336 N H O
H O
R SCoA -
N HN + H
C164 S
N336 N H O
H O
SCoA R
O O
O
- HN +N H
C164 S
N336 N H O
H O
SCoA R O
N HN + H
N336 N H O
H N
HN H
+ C164 S
N336 N H O
H -
A B C
D E
H303
H303
H303 H303
H303
F215
F215 F215 F215
R F215 O O
SCoA
R
O O S
O C164
ᅗ䠎㻌 䊢ᆺ䝫䝸䜿䝍䜲䝗ྜᡂ㓝⣲䛾㓝⣲ᛂᶵᵓ
(A)
άᛶ୰ᚰ
Cysṧᇶࡢ㛤ጞᇶ㉁ࡢ⤖ྜ㸪
(B)࣐ࣟࢽࣝ
CoAࡢ⬺Ⅳ㓟㸪
(C)࣏ࣜࢣࢺ࣓ࢳࣞࣥ
CoA࢚ ࢫࢸࣝࡢ⏕ᡂ㸪
(D)άᛶ୰ᚰ
Cysṧᇶࡢ࣏ࣜࢣࢺ࣓ࢳࣞࣥࡢ⤖ྜ㸪
(E)ࢡࣛࢮࣥᆺࡢ㛢⎔ᛂ➼㸬
㸱㸬࢟ࢲࢳ࢚ࣟ⏤᮶᪂つϪᆺ3.6ࡢ㹖⥺⤖ᬗᵓ㐀ゎᯒᶵ⬟ࡢᣑᙇ
⸆⏝᳜≀࢟ࢲࢳ࢚ࣟ㸦Aloe arborescens㸧ࡽᚓࡽࢀࡓ࣌ࣥࢱࢣࢱࢻࢡࣟࣔࣥྜᡂ㓝⣲㸦PCS㸧
࢜ࢡࢱࢣࢱࢻྜᡂ㓝⣲㸦OKS㸧ࡣ㸪ࡇࢀࡲ࡛ࡢ࡞࠸ࡃ᪂ࡋ࠸ࢱࣉࡢϪᆺ
PKS࡛࠶ࡿ
6,7)㸬
࠸ᚤጁ␗࡞ࡿ㓄ิࢆ᭷ࡍࡿࡇࡢ㸰ࡘࡢ㓝⣲ࡣ㸪᳜≀ᬑ㐢ⓗᏑᅾࡍࡿ
CHSࡣ࣑ࣀ㓟ࣞ࣋ࣝ
࡛⣙
60㸣ࡢ㓄ิ┦ྠᛶࢆ♧ࡍࡶࡢࡢ㸪CHSࡢࡼ࠺ࢼࣜࣥࢤࢽࣥ࢝ࣝࢥࣥྜᡂ⬟ࡣ♧ࡉࡎ㸪ࡑࢀࡒࢀ
㸳ศᏊ࠶ࡿ࠸ࡣ㸶ศᏊࡢ࣐ࣟࢽࣝ
CoAࢆ┤᥋⦰ྜࡋ࡚ⰾ㤶᪘࣏ࣜࢣࢱࢻࢆ⏕ᡂࡍࡿ㸦ᅗ㸱㸪㸲㸧㸬
PCSࡀ⏘⏕ࡍࡿࢡࣟࣔࣥࡣ㸪ᢠႍᜥ࣭ᢠࣞࣝࢠ࣮⸆ࡢ࣮ࣜࢻྜ≀ࡋ࡚᭷ྡ࡞ࢣ࣮ࣜࣥ➼ࡢ⏕⌮άᛶࣇ
ࣟࢡࣟࣔࣥࡢ⏕ྜᡂ๓㥑య࡞ࡿ㸬୍᪉㸪
OKSࡀ⏘⏕ࡍࡿ
SEK4/SEK4bࡣ㸪ᨺ⥺⳦ࡢϩᆺࡢ
minimal PKS㸦㑏ඖ㓝⣲➼ࡢࢧࣈࣘࢽࢵࢺࢆḞⴠࡉࡏࡓϩᆺ
PKSࡢ᭱ᑠ༢ࡢ㓝⣲」ྜయ㸧ࡀ⏘⏕ࡍࡿ௦ㅰ⏘≀
ࡋ࡚▱ࡽࢀ࡚ࡣ࠸ࡿࡶࡢࡢ㸪Ϫᆺ㓝⣲ࡼࡿ࣐ࣟࢽࣝ
CoAࡢ㸶ศᏊࡢ⦰ྜࡣࡇࢀࡀ᭱ึ࡛࠶ࡾ㸪᭱ከ
࡛࠶ࡗࡓ㸬
M
M s C H1 S---------- M V S V SE I R K A Q R AEGPA TI L A I G T ANPAN C VEQS TY P D F Y FK IT N S E HK T E L KEK FQRMC DKSM I KRR YM P s S T S 1 -------- M G G V D F E G FR KL Q R ADGFASI L A I G T ANP P NA VDQS TY P D F Y F RITG NE HN T E L KDK FKR I C E R S AI KQR YM G h 2 P S1 ----- M G S Y S S D D VEVI REA GR AQGLA TI L A I G T ATP P N C VAQA DY P DYY F RVTKS E HMV DL KEK FKR I C EK TAI K K R YL A a P C 1S M S S L S N S L P L M E D V Q GI R K A QKADG T A TV M A I G T AHP PH I FP QD TYADVY F RAT N S E HKV E L KKK FD HI C KK T M IGK R YF A a O K1SM S S L S N A S H L M E D V Q GI R K A Q R ADG T A TV M A I G T AHP PH I FP QD TYAD F Y F RAT N S E HKV E L KKK FDR I C KK T M IGK R YF
M s C H7 1 YS L T E EIL KEN P NVCE Y M AP- S LDA R Q DM VV V EV PRL G K E A A V K A IKE W GQ P K SKI T H LIV C T TSG V D M P G A DYQL TK L L G P
P s S T S7 3 YL T E EIL K K N PD VCAFVEV P S LDA R QA M L A M EV PRLAK E A D EK A IQE W GQ SK SGI T H LI F CSTT T PDLP G A DF E VA K L L G G
G h 2 P7S6 AL T ED YLQ EN PT MCEFM AP- S L N A R Q DL VV TG V PML G K E A A V K A IDE W GL P K SKI T H LI F C T TAG V D M P G A DYQL VK L L G A
A a P C8S1 N Y DE EFL K KY P NI T S Y DE P- S L NDR Q DI CV P G V PAL GTE A A V K A IEE W GR P K SEI T H LVF C TS CG V D M PS A DFQCA K L L G A
A a O K8 S1 N Y DE EFL K KY P NI T SFDE P- S L NDR Q DI CV P G V PAL GAE A A V K A IAE W GR P K SEI T H LVF C TS CG V D M PS A DFQCA K L L G
M
M s C 1H5S0LRPYV K R YM M Y Q Q G CFA G G T V L RLA K D L A E N N K G A R V L V V C S EVT AV TF R G P SDT H L D S L V G Q A L F G D G A A A LI V G S D PV P s S T1S5 3LHPSV K RV GV FQHG CFA G G T V L RMA K D L A E N NRG A R V L VI C S ETT AV TF R G P S E T H L D S L V G Q A L F G D G A CA LI V GAD P I G h 2 P1S5 5LSPSV K R YM L Y Q Q G CAA G G T V L RLA K D L A E N N K GSR V LIV C S EIT A I LFH G P N ENH L D S L VAQ A L F G D G A A A LI V G SGPH A a P C1 6S 0LH A NVN KYC I YMQ G CYA G G T VMRYA K D L A E N NRG A R V L V V CAE L T I M M LR AP N E T H L DN A IGI SL F G D G A A A LI IG S D P I A a O 1K6S0LR T NVN KYCV YMQ G CYA G G T VMRYA K D L A E N NRG A R V L V V CAE L T I I G LR G P N ESH L DN A IGN SL F G D G A A A LI V G S D P I
M s C 2H3S0P E IE K PIF EM VWT A Q T I APD S EGA ID GH L R E A G L T FHLLK D V PG I VSKN I T K AL VEA FE P LG IS - --DYN SIF W IAH P G G P
P s S T2S3 3P QV E KA CF E I VWT A Q T VVP N S EGA IG G K VR EVG L T FQLK G AV PD L I SAN I ENCMVEA FS Q F KIS - --D W N KL F WV VH P G G G
G h 2 P2S3 5L AV ERPIF E I VSTDQ TI LPD TEKAV K LH L R EGG L T FQLH R D V PL M V A KN I EN A A E KAL S P LG I T- --D W N SVF WM VH P G G A
A a P C2 4S 0IG V E K PMF E I VCTKQ T VI P N TED VI HLH L R ETGM MFYL S K G SPMT I S N NV EAC L I D VFK S VG I TP P ED W N S L F W IPH P G G A
A a O 2K4S0IG V E K PMF E I VC A KQ T VI P N S ED VI HLHMR E A G LMFY MS K DSPET I SNNV EAC L VD VFK S VGMTP P ED W N S L F W IPH P G G
M
M s C 3H0S7PA I L D Q V EQK LALKP E KM NA T REV L S E Y G N MSS A C V L F I L D E M R K K ST Q N G LKT T G E G L E W G V L F G F G P G L TIE T V V L R S P
P s S T3S1 0PA I L DRV E A K LNLDPTKLI P T RHVMS E Y G N MSS A CF HF I L DQ TR KASL E N GF ST T G E G L E MG V L F G F G-G L TIE T V V LKS G h 2 P3S1 2R A I L D Q V ERK LNLK E DKLR A SRHV L S E Y G N LIS A C V L F II D EVR KRSMAE GK ST T G E G LD CG V L F G F G P G MT V E T V V L R S A a P C3 2S 0R A I L D Q V E A K LKLRP E KFR A ARTV LW DY G N MVS ASVG YI L D E M RRK S A AK G LETYG E G L E W G V LLG F G P G IT V E TI LLHS A
A a O 3K2S0R A I L D Q V E A K LKLRP E KFR A T RTV LW D CG N MVS A C V LYI L D E M RRK S AD E G LETYG E G L E W G V LLG F G P G MT V E TI LLHS
M
M s C 3H8S7VA I --------- 33 8 9 P s S T3S8 9V PI Q - ------- 33 9 2 G h 2 P3S9 2VR V T A A V A N G N - 44 0 2 A a P C4 0S 0LPL M - ------- 44 0 3 A a O 4K0S0LPL M - ------- 44 0 3
338 256
197 Cys
His
Asn
ᅗ䠏㻌 䊢ᆺ
3.6ࡢ䜰䝭䝜㓟㓄ิ䛾ẚ㍑
MsCHS㸹Medicago sativa CHS㸪PsSTS㸹Pinus sylvestris STS㸪Gh2PS㸹Gebera hybrida 2-PS㸪AaPCS㸹Aloe arboescens PCS㸪AaOKS㸹A.arborescens OKS㸬ゐ፹ṧᇶCys-His-Asn
ࢆ⅊Ⰽ࡛㸪࢟ࣕࣅࢸࢆᵓᡂࡍࡿ
197, 256, 338
␒ṧᇶ㸦CHS ࢼࣥࣂࣜࣥࢢ㸧ࢆ▮༳࡛♧ࡍ㸬
CoAS OH O O
PCS WT
O
O HO
OH
CoAS OH O O
OKS WT & PCS M207G
5
x8
xO SEnz O
O O
O O
O
HO O
HO OH O
O O SEnz O
O
O O
O
HO O
OH O HO
O
O O SEnz
O O
O O
O O O
O
O
O OH HO CoAS OH O
O O
PCS F80A/Y82A/M207G
9
xO O
O O O
O SEnz O O
O
-CO2
OKS N222G
CoAS OH O O
10
xO OH
O
HO O
HO O
O O SEnz O
O O O O
OH OH
O O
OKS F66L/N222G
CoAS OH O O
12
xO OH
O
HO O
O
O O SEnz
O O O
O
OH OH
O O O O
O HO
OH 5,7-dihydroxy-2-methylchromone
nonaketide naphtopyrone
SEK4
SEK4b
SEK15
TW95a
ᅗ㸲 ࢚ࣟ⏤᮶
3&6
2.6ࡢ㒊≉␗ⓗኚ␗ᑟධࡼࡿ࣐ࣟࢽࣝ
&R$⦰ྜᩘࡢไᚚ
࣑ࣀ㓟࡛ࣞ࣋ࣝ࠸
92%࠸࠺㠀ᖖ㧗࠸㓄ิ┦ྠᛶࢆ♧ࡍࡇࡢ㸰ࡘࡢ㓝⣲ࡀ㸪ࡇࡢࡼ࠺ࡃ␗࡞ࡿ⏕ᡂ≀ࢆ࠼ࡿࡢࡣఱᨾ㸪࣐ࣟࢽࣝ
CoAࡢ⦰ྜᅇᩘࡢ㐪࠸ࢆỴᐃࡍࡿせᅉࡣఱ㸽ࡇࢀࡽ㸰 ࡘࡢ㓝⣲࠾࠸࡚ࡣ㸪㸱ࡘࡢゐ፹ṧᇶ
Cys164㸪His303㸪Asn336ࡀࡍ࡚ಖᏑࡉࢀ࡚࠸ࡿ୍᪉࡛㸪Ϫᆺ
PKSࡢࣉࣟࢺࢱࣉࡶゝ࠼ࡿ
CHSࡢάᛶ୰ᚰ࢟ࣕࣅࢸࢆᵓᡂࡍࡿ࣑ࣀ㓟ṧᇶ
Thr197㸪Gly256㸪 Ser338ࡀ
5)㸪PCS ࡛ࡣ
Met207/Leu266/Val351㸪OKS࡛ࡣ
Gly207/Leu266/Val351⨨ࡉࢀ࡚࠸ࡿࡢࡀ≉
ᚩⓗ࡛࠶ࡿ㸦ᅗ㸱㸧㸬ࡑࡇ࡛ᡃࠎࡣ㸪CHS ࡢ
Thr197ṧᇶࡀ㸪PCS ࠾࠸࡚ࡣ
Met207㸪ࡲࡓ㸪OKS
࠾࠸࡚ࡣ
Gly207⨨ࡉࢀ࡚࠸ࡿࡇ╔┠ࡋ㸪
PCSࡢ
Met207ࢆ
Glyኚࡋࡓ㒊≉␗ⓗኚ␗㓝⣲
ࢆసᡂࡋ࡚ኚ␗ࡀ㓝⣲άᛶཬࡰࡍᙳ㡪ࡘ࠸࡚⢭ᰝࡋࡓ㸬ࡑࡢ⤖ᯝ㸪PCS ࡢ
M207G⨨యࡢ㓝⣲ά ᛶࡀⓗኚࡋ㸪㸳ศᏊࡽ㸶ศᏊ࣐ࣟࢽࣝ
CoAࡢ⦰ྜᅇᩘࢆቑຍࡋ࡚㸪OKS ࡢ⏕ᡂ≀࡛࠶ࡿ
SEK4/SEK4b
ࢆ⏕ᡂࡍࡿࡇࡀุ᫂ࡋࡓ㸦ᅗ㸲㸧㸬
ḟ㸪PCS 㔝⏕ᆺ㸪ཬࡧ㸪ࡑࡢ
M207Gኚ␗ᆺ㓝⣲ࡘ࠸࡚㸪1.6 Å ࡢศゎ⬟࡛⤖ᬗᵓ㐀ࢆゎ᫂ࡋࡓ
8)㸬 ᇶ㉁≉␗ᛶ⏕ᡂ≀≉␗ᛶࡣ᫂ࡽ␗࡞ࡿࡶࡢࡢ㸪࣑ࣀ㓟࡛ࣞ࣋ࣝ࠸
60%ࡢ┦ྠᛶࢆ♧ࡍCHSࡢ⤖ᬗᵓ㐀㸪άᛶ୰ᚰࢆᵓᡂࡍࡿṤࡢ࣑ࣀ㓟ṧᇶࢆ㔜ࡡࡿࡇࡀྍ⬟࡛࠶ࡗࡓ㸬୍᪉㸪άᛶ୰ᚰ
࢟ࣕࣅࢸࡢࡁࡉࡣ
PCSࡢ᪉ࡀ᫂ࡽᑠࡉࡃ㸪ࡋࡶ
CHSࡢάᛶ୰ᚰ࢟ࣕࣅࢸぢ࠸ࡔࡉࢀࡓ ࢡ࣐ࣟࣝ⤖ྜ࣏ࢣࢵࢺࡀ㸪PCS ࡢάᛶ୰ᚰ࢟ࣕࣅࢸࡽḞᦆࡋ࡚࠸ࡿࡇࡀ♧ࡉࢀࡓ㸦ᅗ㸳㸧㸬 ࡉࡽ㸪PCS M207G ኚ␗㓝⣲ࡢ
X⥺⤖ᬗᵓ㐀ゎᯒ◊✲ࢆ㐍ࡵࡓ⤖ᯝ㸪Met207 ࢆ
Gly⨨ࡍࡿ
ࡇ࡛㸪ࡑࢀࡲ࡛ᚋ᪉ࡶࡶᇙࡶࢀ࡚࠸ࡓ᪂つ࣏ࢣࢵࢺࡀ㸪M207G ኚ␗㓝⣲ࡢ࢟ࣕࣅࢸࡢ୍㒊
࡞ࡾ㸪ࡑࡢࡁࡉࡀⓗኚࡍࡿࡇࡀ♧ࡉࢀࡓ㸦ᅗ㸳㸧㸬ᮏ⤖ᯝࡣ㸪M207G ኚ␗ࡢᑟධࡼࡾ㸪 ᪂つ࣏ࢣࢵࢺࡢධࡾཱྀࡀ㛤ࡁ㸪ࡇࡢ᪂つ࣏ࢣࢵࢺࢆ⏝ࡍࡿࡇ࡛㸪PCS M207G ኚ␗㓝⣲ࡀ࣏ࣜࢣࢱ
ࢻ㙐ࡢఙ㛗ࢆࡉࡽ㐍⾜ࡉࡏ࡚㸪㸶ศᏊࡢ࣐ࣟࢽࣝ
CoA⦰ྜࢆྍ⬟ࡋࡓ⪃ᐹ࡛ࡁࡿ㸦ᅗ㸳㸧㸬ࡲ
ࡓ㸪
PCS࠾࠸࡚ࡣ㸪
STSࡳࡽࢀࡿࡼ࠺࡞㛢⎔ᛂࡢไᚚ㔜せࡉࢀࡿ
Ser338ṧᇶ㏆ഐࡢỈศᏊࢆ
ࡋࡓỈ⣲⤖ྜࡢࢿࢵࢺ࣮࣡ࢡ
9)ࡣほᐹࡉࢀࡎ㸪༢άᛶ୰ᚰ࢟ࣕࣅࢸࡢࡁࡉᙧ≧ࡢኚࡼࡗ
࡚⏕ᡂ≀ࡢ≉␗ᛶࡀỴᐃࡉࢀࡿࡶࡢ⪃࠼ࡽࢀࡓ㸬ࡑࡇ࡛㸪
PCSࡢࡉࡽ࡞ࡿゐ፹ᶵ⬟ࡢᣑᙇࢆ┠ⓗࡋ
࡚㸪PCS M207G ኚ␗㓝⣲ࡢ࣏ࢣࢵࢺࡢᗏ㠃ࢆᙧᡂࡍࡿ
Phe80, Tyr82ࡢ㸰ࡘࡢⰾ㤶᪘ṧᇶࢆ㸪ྠ
Ala࡛⨨ࡋࡓ
F80A/Y82A/M207G୕㔜ኚ␗㓝⣲ࢆసᡂࡋࡓࡇࢁ㸪ᗘࡣ࣐ࣟࢽࣝ
CoA㸷ศᏊࢆ⦰ྜࡋ࡚㸪ࡇࢀࡲ࡛ࡢ࡞࠸㸱⎔ᛶࢼࣇࢺࣃࣟࣥ㦵᱁ࢆ᭷ࡍࡿ㠀ኳ↛ᆺ᪂つࣀࢼࢣࢱࢻࢆ⏕ᡂࡍࡿࡇ
ᡂຌࡋࡓ㸦ᅗ㸲㸪㸳㸧
10)㸬
୍᪉㸪ᮏ᮶㸶ศᏊࡢ࣐ࣟࢽࣝ
CoAࢆ⦰ྜࡍࡿ
OKSࡘ࠸࡚ࡶ㸪2.6 Å ࡢศゎ⬟࡛⤖ᬗᵓ㐀ࢆゎ᫂ࡋ㸪
PCS
ࡢ
M207Gኚ␗㓝⣲ࡰྠ୍ࡢάᛶ୰ᚰ࢟ࣕࣅࢸࢆ᭷ࡍࡿࡇࢆ᫂ࡽࡋࡓ㸦ᅗ㸳㸧
11)㸬ࡲ
ࡓ㸪࣏ࣜࢣࢱࢻ㙐ࡀఙᙇࡋ࡚࠸ࡃ㝿ቨ࡞ࡿ
Asn222ṧᇶ
Glyኚ␗ࢆᑟධࡋࡓ⤖ᯝ㸪࣐ࣟࢽࣝ
CoAࡢ⦰ྜᅇᩘࡀ㸯㸮ศᏊࡲ࡛ᣑࡋ࡚㸪࣋ࣥࢰࣇ࢙ࣀࣥㄏᑟయ
SEK15ࢆ༢୍⏕ᡂ≀ࡋ࡚㧗⋡࡛⏕ᡂ
ࡍࡿࡇࢆぢฟࡋࡓ㸦ᅗ㸲㸧
11)㸬ࡉࡽ㸪ࡇࡢኚ␗㓝⣲ࡢ
X⥺⤖ᬗᵓ㐀ゎᯒࡶᡂຌࡋ㸪N222G ኚ␗ࡢ
ᑟධࡼࡗ࡚࢟ࣕࣅࢸࡀࡉࡽᣑࡍࡿࡇ㸦ᅗ㸳㸧
12)㸪ཬࡧ㸪ࡑࡢ࣏ࢣࢵࢺࡢᗏ㒊ࢆᙧᡂࡍࡿ
F66ṧᇶࢆ
N222Gኚ␗ྠ
Leu⨨ࡍࡿࡇࡼࡾ㸪㸯㸰ศᏊࡲ࡛࣐ࣟࢽࣝ
CoAࡢ⦰ྜᅇᩘࡀᣑ
ࡋ࡚㸪ࢼࣇࢺࣇ࢙ࣀࣥㄏᑟయ
TW95aࢆ⏕ᡂࡍࡿࡇࢆ᪤☜ㄆࡋ࡚࠸ࡿ㸦ᅗ㸲㸪㸳㸧
12)㸬
ᅗ㸳 3&6
2.6ࡢ㔝⏕ᆺཬࡧኚ␗㓝⣲
&+6ࡢάᛶ୰ᚰ࢟ࣕࣅࢸࡢẚ㍑ᶍᘧᅗ
X
⥺ ⤖ ᬗ ᵓ 㐀 ゎ ᯒ ࡼ ࡾ ᚓ ࡽ ࢀ ࡓ ࢱ ࣥ ࣃ ࢡ ㉁ ࡢ ❧ య ᵓ 㐀 ࡼ ࡿ ẚ ㍑ 㸬 ࡇ ࡢ ࠺ ࡕ
PCSࡢ
F80A/Y82A/M207G
୕㔜ኚ␗㓝⣲
OKSࡢ
F66L/N222G㔜ኚ␗㓝⣲ࡢ❧యᵓ㐀ࡣ㸪ศᏊࣔࢹࣜࣥࢢ
ࡼࡾண ࡋࡓࡶࡢ㸬
㸲㸬ேᕤᇶ㉁ࢆࣉ࣮ࣟࣈࡋࡓ㠀ኳ↛ᆺྜ≀ࡢฟ
ୖ㏙ࡣࡋ࡞ࡗࡓࡀ㸪ᡃࠎࡣ㸪Ꮫⓗྜᡂࡋࡓேᕤᇶ㉁ࢆࣉ࣮ࣟࣈࡋ࡚㓝⣲స⏝ࡉࡏࡿࡇ
ࡼࡾ㸪Ϫᆺ
PKSࡀ㓝⣲ࡋ࡚ࡣ␗ࡶゝ࠼ࡿᐶᐜ࡞ᇶ㉁≉␗ᛶࢆ♧ࡍࡇࢆ᫂ࡽࡋ࡚ࡁࡓ
2)㸬
࠼ࡤ㸪CHS
STSࡣ㸪ᮏ᮶㸪ࢡ࣐ࣟࣝ
CoAࢆ㛤ጞᇶ㉁ࡋ࡚㸪ࡑࢀࡒࢀࢼࣜࣥࢤࢽࣥ࢝ࣝࢥࣥࣞ
ࢫ࣋ࣛࢺ࣮ࣟࣝࡢኚࢆゐ፹ࡍࡿϪᆺ
PKS࡛࠶ࡿࡀ㸦ᅗ㸯㸧㸪ࢡ࣐ࣟࣝᇶࡢⰾ㤶⎔ࡢỈ㓟ᇶࢆࣇࢵ
⣲ࡸ࣓ࢺ࢟ࢩᇶ࡛⨨ࡋࡓ࢚ࢫࢸࣝ㸪࠶ࡿ࠸ࡣ㸪ⰾ㤶⎔ࢆࣇࣛࣥࡸࢳ࢜ࣇ࢙ࣥ➼ࡢ࣊ࢸࣟⰾ㤶⎔࡛⨨
ࡋࡓᇶ㉁ࢼࣟࢢࢆస⏝ࡉࡏࡿ㸪࡚ࡀ㓝⣲ᛂࡢ㛤ጞᇶ㉁ࡋ࡚ᶵ⬟ࡋ㸪࣐ࣟࢽࣝ
CoAࢆ㸱ศᏊ
ࡲ࡛⦰ྜࡋ࡚㸪୍㐃ࡢ㠀ኳ↛ᆺ᪂つྜ≀ࢆ⏕ᡂࡍࡿ㸦ᅗ㸴㸧
13, 14)㸬
2f : X = O 2g: X = S
4a: X = OH 4b: X = F
1a: X = OH 1b: X = F 1c: X = Cl 1d: X = Br 1e: X = OCH3
3f : X = O 3g: X = S
4f : X = O 4g: X = S
5f : X = O 5g: X = S 1f : X = O
1g: X = S
2a: X = OH 2b: X = F 2c: X = Cl 2d: X = Br 2e: X = OCH3
3a: X = OH 3b: X = F 3c: X = Cl 3d: X = Br 3e: X = OCH3
5a: X = OH 5b: X = F +
2
x malonyl-CoA +3
x malonyl-CoACHS & STS
CHS STS
+
3
x malonyl-CoA +3
x malonyl-CoACoAS O
X
CoAS O
X
O
OH O
X
O
OH O
X
O
OH O
O
X
O
OH O
O X
OH OH HO
O
X
OH OH HO
O X
OH HO
X
OH HO
X
ᅗ㸴 &+6
676ࡀ♧ࡋࡓᐶᐜ࡞ᇶ㉁≉␗ᛶ₯ᅾ⬟ຊ
ࡑࡇ࡛㸪OKS ࢡ࣐ࣟࣝ
CoAࢆ㛤ጞᇶ㉁ࡋ࡚స⏝ࡉࡏࡓ⤖ᯝ㸪ࢡ࣐ࣟࣝ
CoA㸳ศᏊ࠶ࡿ࠸
ࡣ㸴ศᏊࡢ࣐ࣟࢽࣝ
CoAࡀ⦰ྜࡢᚋ㸪ࣝࢻ࣮ࣝᆺ⦰ྜࡼࡾⰾ㤶⎔ࢆᙧᡂࡋࡓ㠀ኳ↛ᆺ᪂つ
C19ࢫࢳ
ࣝ࣋ࣥཬࡧ
C21࢝ࣝࢥࣥࡀ⏕ᡂࡉࢀࡿࡇࢆぢฟࡋࡓ㸦ᅗ㸵㸧
11)㸬୍᪉㸪⤖ᬗᵓ㐀ᇶ࡙ࡁάᛶ୰ᚰ࢟
ࣕࣅࢸࢆᣑࡋࡓ
OKSࡢ
N222Gኚ␗㓝⣲ࢡ࣐ࣟࣝ
CoAࢆ㛤ጞᇶ㉁ࡋ࡚స⏝ࡉࡏࡿ㸪⏕ᡂ≀
ࡢྜࡀⓗኚࡋ࡚㸪SEK4/SEK4b ࡢ⏕ᡂ㔞ࡀῶᑡࡍࡿ୍᪉࡛㸪C
21࢝ࣝࢥࣥࡢ⏕ᡂ㔞ࡀ㣕㌍ⓗ
ቑࡋ㸪⏕ᡂ≀ࡋ࡚࠼ࡿࡇࢆぢฟࡋࡓ㸦ᅗ㸵㸧
11)㸬ᮏኚ␗㓝⣲ࡣ㸪C
21࢝ࣝࢥࣥࡢ⏕ᡂࡼࡾ
≉ࡋࡓゝ࠼ࡿ㸬≀㉁⏕⏘ࢆ⪃࠼ࡿ࠺࠼࡛⏕⏘ᛶࡢྥୖࡶ㔜せ࡞せ⣲࡛࠶ࡾ㸪Ⅼኚ␗ࡢᑟධࡼࡾ࣐
ࣟࢽࣝ
CoA⦰ྜᅇᩘࢆቑຍࡉࡏࡓࡔࡅ࡛࡞ࡃ㸪ᇶ㉁≉␗ᛶࢆࡶᖜኚࡉࡏࡓࡇࡣὀ┠್ࡍࡿ㸬 Ϫᆺ
PKSࡢ⏕యゐ፹ࡋ࡚ࡢࡉࡽ࡞ࡿྍ⬟ᛶࢆ♧ࡍ⤖ᯝ࡛࠶ࡿ⪃࠼࡚࠾ࡾ㸪⌧ᅾ㸪࣐ࣟࢽࣝ
CoA⦰
ྜᅇᩘࡢࡉࡽ࡞ࡿቑᇶ㉁≉␗ᛶࡢᨵኚࢆ┠ᣦࡋ㸪ᇶ㉁ࡸ㓝⣲ᛂ୰㛫యࢼࣟࢢࡢ」ྜయ❧యᵓ 㐀ゎᯒࢻࢵ࢟ࣥࢢࢩ࣑࣮ࣗࣞࢩࣙࣥࡼࡿ㓝⣲ゐ፹ᶵᵓࡢゎᯒኚ␗ᑟධᐇ㦂ࡀ㐍⾜୰࡛࠶ࡿ㸬
O O OH CoAS
O O OH CoAS
6
x+ HO
OH O
O
HO O
O O O
O
O SEnz
O
OH OH
5
x+
O SEnz O
O O
O O HO HO
OH
O
OH OH O
O CoAS
O
OH
SEK4
SEK4b
SEK4 SEK4b
min min
A280
A280
C21 chalcone
C19 stilbene
C21 chalcone
C19 stilbene
OKS WT OKS N222G
C21 chalcone
C19 stilbene
OKS WT & OKS N222G
ᅗ䠓㻌 ࢡ࣐ࣟࣝ
&R$ࢆ㛤ጞᇶ㉁ࡋࡓࡁࡢ
2.6㔝⏕ᆺࡑࡢ
1*ኚ␗㓝⣲ࡢᛂ⏕ᡂ≀
㸳㸬ࢺ࢘ࢤࢩࣂ⏤᮶3.6ࢆ⏝ࡋࡓ㠀ኳ↛ᆺ᪂つࣝ࢝ࣟࢻࡢฟ
ࢺ࢘ࢤࢩࣂ
Huperzia serrata⏤᮶
PKS1ࡣ㸪Ϫᆺ
PKSࡢ୰࡛ࡶ≉ᐶᐜ࡞ᇶ㉁≉␗ᛶࢆ᭷ࡍࡿϪᆺ㓝
⣲࡛࠶ࡿ
15)㸬ୖ㏙ࡋࡓࡼ࠺㸪Ϫᆺ
PKSࡣ㸪C, H, O ཎᏊ࡛ᵓᡂࡉࢀࡿ㸪༢⣧࡞ࠕ࢝ࣝ࣎ࢽࣝࡢᏛࠖ
ࢆゐ፹ࡍࡿࡀ㸪ࡇࡇ࡛㸪ࡉࡽ
NཎᏊ➼ࡢ࣊ࢸࣟཎᏊࢆᑟධࡋࡓேᕤᇶ㉁ࢆస⏝ࡉࡏࢀࡤ㸪
NཎᏊࡢሷ ᇶᛶࢆ⏝ࡋࡓ᪂ࡓ࡞
C-N⤖ྜࡸ
C-C⤖ྜࡢᙧᡂࡶྍ⬟࡞ࡿ㸬ࡑࡇ࡛㸪PKS1 㸪࢝ࣝࣂࣔࣝᇶࢆ
᭷ࡍࡿᏳᜥ㤶㓟ࡸࣆࢥࣜࣥ㓟➼ࡢ
CoA࢚ࢫࢸࣝࢆ࣐ࣟࢽࣝ
CoA㸦࠶ࡿ࠸ࡣ࣓ࢳ࣐ࣝࣟࢽࣝCoA㸧ࡶస⏝ࡉࡏࡓ⤖ᯝ㸪㸰ศᏊࡢ࣐ࣟࢽࣝ
CoAࡢ⦰ྜࡢᚋ㸪ᛂᛶᐩࡴ
β-࣏ࣜࢣࢺ࣓ࢳࣞࣥ୰㛫య
ࡽࢩࢵࣇሷᇶࡢᙧᡂࢆࡋࡓ㸰ᅇࡢ
C-N⤖ྜᙧᡂᛂࡀ㐍⾜ࡋ࡚㸪6.5.6 ⦰ྜ⎔ᵓ㐀ࢆࡶࡘ㠀ኳ↛ᆺ᪂
つࣆࣜࢻࢯࣥࢻ࣮ࣝ㸦ࡲࡓࡣࣆࣜࢻࣥࢻࣜࢪࣥ㸧㦵᱁ࢆ⏕ᡂࡍࡿࡇࡀุ᫂ࡋࡓ㸦ᅗ㸶㸧
15)㸬
O O OH CoAS
X SCoA
NH2 O
O
2 x
+
X
NH2 O
O
SEnz O R O
R
X N O
O
OH R R X = C: 2-carbamoylbenzoyl-CoA
X = N: 3-carbamoylpicolinyl-CoA
R = H or CH3
R = H or CH3 R
O O
OH CoAS
SCoA NH2 O
O
2 x
+ NH2
O
O
SEnz O O
N O
O
OH 3-carbamoyl-2-naphthoyl-CoA
ᅗ䠔㻌 䝖䜴䝀䝅䝞⏤᮶
㻌㻼㻷㻿㻝 䛜♧䛧䛯₯ᅾⓗゐ፹⬟ຊ䛸㠀ኳ↛ᆺ᪂つ䜰䝹䜹䝻䜲䝗㦵᱁䛾⏕⏘㻌 㻌
Phe225 Phe225 Phe225
O N O S
H
H O
N O
H H S
O
N O O
O
Phe225
+ malonyl-CoA + malonyl-CoA
Cys174 Ser348 Cys174 Ser348 Cys174 Ser348 Cys174 Ser348
Phe225
Cys174 Ser348
Phe225
Cys174 Ser348
S
HN O
OH O S O
HN O S O
O
O O O
O O
O
N O O
HO S O
O O
O N H H H
H H
H H
H
Asn346 N
O
H Asn346 H
N O
H Asn346 H
N O
H Asn346 H
N O
H H
Asn346 N
O
H Asn346 H
N O
H H
ᅗ㸷 3.6 㔝⏕ᆺࡼࡿ ࣆࣜࢻࢯࣥࢻ࣮ࣝ㦵᱁ࡢ⏕⏘
Ϫᆺ
PKSࡀ㸰ᅇࡢ
C-N⤖ྜᙧᡂᛂࢆゐ፹ࡋࡓࡢࡣࡇࢀࡀ᭱ึ࡛࠶ࡿ㸬ࡑࡇ࡛㸪PKS1 ࡀゐ፹ࡍࡿࣆ
ࣜࢻࢯࣥࢻ࣮ࣝ㦵᱁ࡢ㓝⣲ᛂᶵᵓࡢゎ᫂ࡉࡽ࡞ࡿ᪂つࣝ࢝ࣟࢻࡢฟࢆ┠ⓗࡋ࡚㸪
PKS1ࡢ
X⥺⤖ᬗᵓ㐀ゎᯒ㸪㓝⣲ᛂ୰㛫యࡢࢻࢵ࢟ࣥࢢࢩ࣑࣮ࣗࣞࢩࣙࣥࢆ⾜ࡗࡓ
15)㸬ࡲࡎ㸪
2.0 Åࡢศゎ⬟࡛
PKS1ࡢ⤖ᬗᵓ㐀ࢆᚓࡓ
12)㸬ḟ㸪ࣆࣜࢻࢯࣥࢻ࣮ࣝࡢ㓝⣲ᛂ୰㛫యࡢ❧యࣔࢹ
ࣝࢆసᡂࡋ㸪PKS1 ࡢ⤖ᬗᵓ㐀ࡢࢻࢵ࢟ࣥࢢࢩ࣑࣮ࣗࣞࢩࣙࣥࢆ⾜ࡗࡓ⤖ᯝ㸪άᛶ୰ᚰ࢟ࣕࣅࢸࢆ
ᵓᡂࡍࡿ
Ser348ࡀ㸪࣐ࣟࢽࣝ
CoAࡢ⦰ྜᅇᩘ㛢⎔ᛂࡢไᚚ≉㔜せ࡞ᙺࢆ₇ࡎࡿྍ⬟ᛶࡀ♧
ࡉࢀࡓ㸦ᅗ㸷㸧㸬ࡑࡇ࡛㸪Ser348 ࢆ
Gly, Cys, Thr, Alaࡲࡓࡣ
Val⨨ࡋࡓⅬኚ␗㓝⣲ࢆసᡂࡋ࡚㸪ࡑࡢ 㓝⣲άᛶࡘ࠸࡚⢭ᰝࡋࡓࡇࢁ㸪
S348Gኚ␗యࡀ㸪
6.5.6⦰ྜ⎔ᵓ㐀ࡢࣆࣜࢻࢯࣥࢻ࣮ࣝࡢ⏕ᡂ
ࡶ㸪࢝ࣝࣂࣔࣝᏳᜥ㤶㓟ࡢ
CoAࢳ࢚࢜ࢫࢸࣝ㸱ศᏊࡢ࣐ࣟࢽࣝ
CoAࢆ⦰ྜࡢᚋ㸪ࢩࢵࣇሷᇶ ࡢᙧᡂࢆࡋࡓ
C-N⤖ྜ
C-C⤖ྜࡢᙧᡂࢆ㐍⾜ࡋ࡚㸪⎔ᣑࡋࡓ
6.7.6⦰ྜ⎔ᵓ㐀ࢆࡶࡘ㠀ኳ↛ᆺ᪂ つࢪ࣋ࣥࢰࢮࣆࣥ㦵᱁ࢆ࠶ࡽࡓ⏕ᡂࡍࡿࡇࡀุ᫂ࡋࡓ㸦ᅗ㸯㸮㸧㸬⌧ᅾ㸪ࡉࡽ࡞ࡿ㓝⣲ゐ፹ᶵ⬟
ࡢᣑᙇ᪂つࣝ࢝ࣟࢻࡢฟࡀ㐍⾜୰࡛࠶ࡿ㸬୍᪉㸪ࡇࡢࢪ࣋ࣥࢰࢮࣆࣥࡣ㸪࣓ࢳࢩࣜࣥឤཷᛶ 㯤Ⰽࣈࢻ࢘⌫⳦ᑐࡋ࡚㸪ࣂ࢜ࣇ࣒ࣝᙧᡂ㜼ᐖάᛶࢆ♧ࡋࡓ㸦
MIC = 12Pg/ml㸧15)㸬ࣂ࢜ࣇࣝ
࣒ࡢᙧᡂࡣ㸪ேࡢචࡸᢠ⏕≀㉁ᑐࡍࡿ⣽⳦ࡢ㜵ᚚᶵᵓࡢ୍ࡘ࡛࠶ࡾ㸪᭱㏆࡛ࡣࣂ࢜ࣇ࣒ࣝᙧᡂ 㜼ᐖࢆࢱ࣮ࢤࢵࢺࡋࡓᢠ⏕≀㉁ࡢ㛤Ⓨࡶ⯆ࡀᣢࡓࢀ࡚࠸ࡿ㸬ࢪ࣋ࣥࢰࢮࣆࣥㄏᑟయࡀࣂ࢜ࣇ
࣒ࣝᙧᡂ㜼ᐖࢆ♧ࡋࡓࡢࡣࡇࢀࡀ᭱ึ࡛࠶ࡾ㸪ᵓ㐀ᶵ⬟άᛶ┦㛵ࡶ㸪ࣂ࢜ࣇ࣒ࣝᙧᡂ㜼ᐖ ᶵᵓࡶ⯆ࡀᣢࡓࢀࡿࡇࢁ࡛࠶ࡿ㸬
PKS1
PKS1 S348G
ᅗ㸯㸮 3.66* ኚ␗㓝⣲ࡼࡿ ࢪ࣋ࣥࢰࢮࣆࣥ㦵᱁ࡢ⏕⏘
㻌
㸴㸬࠾ࢃࡾ
Ϫᆺ
PKSࡢ␗ࡶゝ࠼ࡿᐶᐜ࡞ᇶ㉁≉␗ᛶ₯ᅾⓗゐ፹⬟ຊࢆά⏝ࡍࡿࡇࡼࡾ㸪ࡲࡓ㸪ྜ⌮
ⓗ࡞ேᕤᇶ㉁ࡢタィ⤖ᬗᵓ㐀ᇶ࡙ࡃᶵ⬟ᨵኚ㓝⣲ࢆ⤌ࡳྜࢃࡏࡿࡇࡼࡾ㸪᪂つ⏕యゐ፹ࡢ㛤Ⓨ
㠀ኳ↛ᆺ᪂つ⏕≀άᛶྜ≀ࡢຠ⋡ⓗ࡞⏕⏘ࡀྍ⬟࡞ࡿ㸬ᅇࡣ⤂ࡋ࡞ࡗࡓࡀ㸪᪤ᡃࠎࡣ㸪 ᮏ᮶㸪Ϫᆺ
PKS
P450㑏ඖ㓝⣲ࡼࡾ㸪㸰ẁ㝵ࡢᛂࢆ⤒࡚⏕ᡂࡍࡿࢸࢺࣛࣁࢻࣟࣅࢫࢹ࣓ࢺ࢟ࢩ ࢡࣝࢡ࣑ࣥࡸ㸪
Iᆺ
PKS㠀ࣜ࣎ࢯ࣮࣒౫Ꮡᛶ࣌ࣉࢳࢻྜᡂ㓝⣲ࡢࣁࣈࣜࢵࢻ⤒㊰ࡼࡗ࡚⏕ྜᡂ ࡉࢀࡿࢸࢺ࣑ࣛࣥ㓟㦵᱁ࢆ㸪Ϫᆺ
PKSࡢࡳࢆ⏝࠸࡚ฟࡍࡿࡇ➼ࡶᡂຌࡋ࡚࠸ࡿ
4, 16)㸬୍᪉㸪Ϫᆺ
PKSࡢᛂᛶᐩࢇࡔ࣏ࣜࢣࢺ࣓ࢳࣞࣥ୰㛫యࡽ㸪ࡉࡽከᵝ࡞ศᏊෆ⎔ᛂࢆᘬࡁ㉳ࡇࡍࡇࡀ
࡛ࡁࢀࡤ㸪ࡇࢀࡲ࡛௨ୖศᏊከᵝᛶᐩࢇࡔከ⎔ᛶ᪂つྜ≀⩌ࡢฟࡀྍ⬟࡞ࡿ㸬ࡋࡋ࡞ࡀࡽ㸪
Ϫᆺ
PKSࡀゐ፹ࡍࡿ㛢⎔ᛂᶵᵓࡘ࠸࡚ࡣᮍࡔ᫂࡞Ⅼࡀከ࠸࠸࠺ࡢࡀ⌧≧࡛࠶ࡾ㸪ᐇ㝿ࡢ
ࡼ࠺ࡋ࡚㛢⎔ᛂࡀ㐍⾜ࡍࡿࡢࡣ⯆῝࠸Ⅼ࡛࠶ࡿ㸬Ⅳ⣲㙐ఙ㛗ᛂࡢ㉳Ⅼ࡞ࡿ
Cysṧᇶࡽࡢ ࢳ࢚࢜ࢫࢸࣝ⤖ྜࡢ㛤ࡼࡿ࣏ࣜࢣࢱࢻ㙐ࡢษࡾฟࡋࢱ࣑ࣥࢢ➼ࡀၥ㢟࡞ࡿࡀ㸪ࡇࢀࡽࡘ
࠸࡚ࡣ
NMRἲࡸࢣ࣑࢝ࣝࣂ࢜ࣟࢪ࣮ࡢᡭἲࢆ⏝࠸࡚ゎ᫂ࡋ࡚࠸ࡃࡇࢆணᐃࡋ࡚࠸ࡿ㸬ࡲࡓ㸪Ϫᆺ
PKSࡢࡼ࠺࡞㦵᱁ᙧᡂ㓝⣲ࡢࡳ࡞ࡽࡎ㸪ࣉࣞࢽࣝᇶ㌿⛣㓝⣲ࡸ㓟㑏ඖ㓝⣲➼ࡢಟ㣭㓝⣲ࡢᇶ㉁≉␗ᛶ
ࡸ₯ᅾⓗゐ፹⬟ຊࡘ࠸࡚ࡶゎᯒࢆ㐍ࡵ㸪ᑗ᮶ⓗࡣ㸪㓴㓝ᕤᏛࡸ᳜≀௦ㅰᕤᏛᒎ㛤ࡋ࡚㸪ྜᡂ⏕
≀Ꮫⓗᡭἲࡼࡿ≀㉁⏕⏘ࡸ㑇ఏᏊᑟධࡼࡿ᪂ᶵ⬟㈿ᙧ㉁㌿యࡢసฟ➼㸪ᐇ⏝౪ࡍࡿ≀㉁⏕⏘
⣔ࡢ㛤Ⓨࡶᣮᡓࡋࡓ࠸㸬
ㅰ㎡
ᮏ◊✲ࡣ㸪ࡋ࡚㸪ᮾிᏛᏛ㝔⸆Ꮫ⣔◊✲⛉ኳ↛≀Ꮫᩍᐊ㸪㟼ᒸ┴❧ᏛᏛ㝔⸆Ꮫ◊✲⛉
⏕⸆࣭ኳ↛≀Ꮫศ㔝㸪ཬࡧ㸪୕⳻Ꮫ⏕⛉Ꮫ◊✲ᡤ࡛⾜ࢃࢀࡓࡶࡢ࡛࠶ࡿ㸬ࡈᣦᑟࡈ㠴᧡ࢆ㈷ࡾࡲ
ࡋࡓᮾிᏛᏛ㝔⸆Ꮫ⣔◊✲⛉࣭㜿㒊㑳ᮁᩍᤵ㸪㟼ᒸ┴❧Ꮫ⸆Ꮫ㒊࣭㔝ཱྀ༤ྖᩍᤵ㸪୕⳻Ꮫ⏕
⛉Ꮫ◊✲ᡤ࣭Ἑ㔝ಇஅ༤ኈ㸪୕⳻Ꮫ࣭ᮡᑿᡂಇ༤ኈ῝⏒࡞ࡿឤㅰࢆ⏦ࡋୖࡆࡲࡍ㸬ࡲࡓ㸪ᮏ◊✲ࢆ
⾜࠺࠶ࡓࡾ୰ᚰⓗᙺࢆᢸࡗ࡚ࡃࢀࡓ㟼ᒸ┴❧Ꮫ⸆Ꮫ㒊࣭㪭ῲΎྐຓᩍࢆࡣࡌࡵ㸪ᑾຊୗࡉࡗࡓከ ࡃࡢ᪉ࠎ࠾♩⏦ࡋୖࡆࡲࡍ㸬
ཧ⪃ᩥ⊩
1) Austin, M.B. & Noel, J.P. (2003) The chalcone synthase superfamily of type III polyketide synthases. Nat.
Prod. Rep.,20, 79-110.
2) Abe, I. & Morita, H. (2010) Structure and function of the chalcone synthase superfamily of plant type III polyketide synthases. Nat. Prod. Rep.,27, 809-838.
3) Morita, H., Shimokawa, Y., Tanio, M., Kato, R., Noguchi, H., Sugio, S., Kohno, T. & Abe, I. (2010) Structure-based mechanism for benzalacetone synthase from Rheum palmatum.Proc. Natl. Acad. Sci. USA, 107, 669-673.
4) Morita, H., Wanibuchi, K., Nii, H., Kato, R., Sugio, S. & Abe, I. (2010) Structural basis for the one-pot formation of the diarylheptanoid scaffold by curcuminoid synthase from Oryza sativa.Proc. Natl. Acad. Sci.
USA,107, 19778-19783.
5) Morita, H., Yamashita, M., Shi, S.P., Wakimoto, T., Kondo, S., Kato, R., Sugio, S., Kohno, T. & Abe, I.
(2011) Synthesis of unnatural alkaloid scaffolds by exploiting plant polyketide synthase. Proc. Natl. Acad.
Sci. USA,108, 13504-13509.
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