4-5-7-8-9成环：合成酶（GART(E3)）

催化反应

[[N-甲酰甘氨脒核苷酸（FGAM）]]+ATP->[[5-氨基咪唑核苷酸（AIR）]]+ADP+$

$化学方程式：$

\usepackage{chemfig}
\begin{document}

\chemfig{
	\fbox{R}-[2,0.8]NH(-[2,0.25]9)
	-[3.5,0.6](-[3.3,0.25]4)(-[4.5,0.7]H_2N)
	=[2,0.8](-[4.8,0.25]5)
	-[0.5,0.8]N(-[5.5,0.25]7)(-[,0.3]H)
	-[6.55,0.8]
		(-[4,0.2]8)
		(=[6,0.4]O)
		(-[,0.4]H)
}

+ATP

\begin{tikzpicture} 
\draw [->] (0,0) to node[above] {GART(E3);^{2+}$} (1,0); 
\end{tikzpicture}

\chemfig{
	\fbox{R}-[2,0.8]N(-[2,0.25]9)
	-[3.5,0.6](-[3.3,0.25]4)(-[4.5,0.7]N(-[2,0.25]3)(-[4,0.3]H_2))
	=[2,0.8](-[4.8,0.25]5)
	-[0.5,0.8]N(-[5.5,0.25]7)(-[,0.3]H)
	=[6.55,0.8]
		(-[4,0.2]8)
		-[5.25,0.6]
}
+ADP+$

\end{document}