Biochemical and Mutational Analysis of a Novel Nicotinamidase from Oceanobacillus iheyensis HTE831
Biochemical and Mutational Analysis of a Novel Nicotinamidase from Oceanobacillus iheyensis HTE831
复制标题
伊赫海洋杆菌 HTE831 新型烟酰胺酶的生化和突变分析
作者：
Guiomar Sánchez;M. García;R. Zapata;H. Takami;F. García;Á. Sánchez
烟酰胺酶催化烟酰胺水解为烟酸和氨，这是NAD+补救途径中的重要反应。本文报道了从深海极端耐盐嗜碱海洋芽孢杆菌（Oeanobacillusiheyensis）HTE 831（OiNIC）中分离得到的一种新的烟酰胺酶。该酶对烟酰胺和几种类似物（包括前药吡嗪酰胺）具有活性。该酶是烟酰胺酶（kcat/Km = 43.5 mM − 1s − 1），而不是吡嗪酰胺酶（kcat/Km = 3.2 mM − 1s − 1）。 对7个关键氨基酸进行了突变分析，首次证实了Cys133和Phe68残基分别使吡嗪酰胺酶活性增加2.9倍和2.5倍的重要性。此外，参与离子金属结合的第四个残基（Glu65）的变化对吡嗪酰胺酶活性有害，使其降低6倍。该残基也参与了本文中描述的厚壁菌属烟酰胺酶的一个新的独特结构基序DAHXXXDXXHPE。系统发育分析表明，OiNIC是第一个描述的杆菌目烟酰胺酶。
Nicotinamidases catalyze the hydrolysis of nicotinamide to nicotinic acid and ammonia, an important reaction in the NAD+ salvage pathway. This paper reports a new nicotinamidase from the deep-sea extremely halotolerant and alkaliphilic Oceanobacillus iheyensis HTE831 (OiNIC). The enzyme was active towards nicotinamide and several analogues, including the prodrug pyrazinamide. The enzyme was more nicotinamidase (kcat/Km = 43.5 mM−1s−1) than pyrazinamidase (kcat/Km = 3.2 mM−1s−1). Mutational analysis was carried out on seven critical amino acids, confirming for the first time the importance of Cys133 and Phe68 residues for increasing pyrazinamidase activity 2.9- and 2.5-fold, respectively. In addition, the change in the fourth residue involved in the ion metal binding (Glu65) was detrimental to pyrazinamidase activity, decreasing it 6-fold. This residue was also involved in a new distinct structural motif DAHXXXDXXHPE described in this paper for Firmicutes nicotinamidases. Phylogenetic analysis revealed that OiNIC is the first nicotinamidase described for the order Bacillales.
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影响因子：
2.9
作者：
French, Jarrod B.;Cen, Yana;Vrablik, Tracy L.;Xu, Ping;Allen, Eleanor;Hanna-Rose, Wendy;Sauve, Anthony A.
通讯作者：
Sauve, Anthony A.
影响因子：
3.9
作者：
Hu, Gang;Taylor, Alexander B.;Hart, P. John
通讯作者：
Hart, P. John
影响因子：
2.9
作者：
Smith BC;Hallows WC;Denu JM
通讯作者：
Denu JM
恶性疟原虫感染的人红细胞中烟酰胺腺嘌呤二核苷酸含量和合成增加。
影响因子：
20.3
作者：
Zerez,CR;RothJr,EF;Schulman,S;Tanaka,KR
通讯作者：
Tanaka,KR
影响因子：
3.5
作者：
HO, SN;HUNT, HD;PEASE, LR
通讯作者：
PEASE, LR