Structural rearrangement accompanying NAD+ synthesis within a bacterial DNA ligase crystal
Structural rearrangement accompanying NAD+ synthesis within a bacterial DNA ligase crystal
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DOI：
10.1016/j.str.2004.05.017
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发表时间：
2004-08-01
期刊：
影响因子：
5.7
通讯作者：
Pinko, C
中科院分区：
文献类型：
--
作者：
Gajiwala, KS;Pinko, C
DNA连接酶是DNA修复和复制的重要酶。真核生物基因组编码需要ATP作为辅因子的连接酶;细菌基因组编码NAD（+）依赖性连接酶。这种底物特异性的差异和NAD（+）依赖性连接酶对细菌存活的重要性使NAD（+）依赖性连接酶成为设计高度特异性抗感染药物的良好靶标。任何这样的结构导向的努力都需要了解酶识别NAD（+）的精确机制。我们报道了NAD（+）识别的原理，通过呈现由烟酰胺单核苷酸（NMN）和AMP在晶格内由粪肠球菌连接酶催化合成NAD（+）。使用相同的蛋白质晶体获得的两种结构中捕获了前所未有的构象变化，这是重新定向蛋白质的两个亚结构域以发生缩合和识别NAD（+）所需的。这里提供的结构数据和序列分析证实并扩展了连接酶腺苷酸化反应的先前功能研究。
DNA ligase is an enzyme important for DNA repair and replication. Eukaryotic genomes encode ligases requiring ATP as the cofactor; bacterial genomes encode NAD(+)-dependent ligase. This difference in substrate specificities and the essentiality of NAD(+)-dependent ligase for bacterial survival make NAD(+)-dependent ligase a good target for designing highly specific anti-infectives. Any such structure-guided effort would require the knowledge of the precise mechanism of NAD(+) recognition by the enzyme. We report the principles of NAD(+) recognition by presenting the synthesis of NAD(+) from nicotinamide mononucleotide (NMN) and AMP, catalyzed by Enterococcus faecalis ligase within the crystal lattice. Unprecedented conformational change, required to reorient the two subdomains of the protein for the condensation to occur and to recognize NAD(+), is captured in two structures obtained using the same protein crystal. Structural data and sequence analysis presented here confirms and extends prior functional studies of the ligase adenylation reaction.