Spectroscopic Study of the EutT Adenosyltransferase from Listeria monocytogenes: Evidence for the Formation of a Four-Coordinate Cob(II)alamin Intermediate.
Spectroscopic Study of the EutT Adenosyltransferase from Listeria monocytogenes: Evidence for the Formation of a Four-Coordinate Cob(II)alamin Intermediate.
复制标题
DOI：
10.1021/acs.biochem.8b00743
复制
发表时间：
2018-08-28
期刊：
影响因子：
2.9
通讯作者：
Brunold TC
中科院分区：
文献类型：
--
作者：
Stracey NG;Costa FG;Escalante-Semerena JC;Brunold TC
来自单核细胞增生李斯特菌的EutT酶（LmEutT）是ATP：钴（I）类咕啉腺苷转移酶（ACAT）家族的成员，其催化从外源性Co（II）类咕啉和ATP生物合成腺苷钴胺素（ACAT Cbl）。除了EutT型ACATs之外，还发现了两种进化上不相关的ACATs，称为PduO和CobA。虽然三种类型的ACATs是非同源的，但它们都产生四配位钴（II）丙氨酸（4C Co（II）Cbl）物质，以促进形成能够攻击共底物ATP的5 '-碳的超亲核Co（I）Cbl中间体。以前的光谱研究的EutT ACAT从沙门氏菌enterica（SeEutT）显示，这种酶需要一个二价金属辅因子的转换5C钴（II）Cbl到4C物种。有趣的是，LmEutT不需要二价金属辅因子的催化活性，这证实了一个有趣的系统发育差异之间的EutT酶。为了探索EutT酶之间金属辅因子需求的这种差异是否与底物特异性或Co（II）Cbl还原机制的差异相关，我们采用了各种光谱技术来探测Co（II）Cbl和cob（II）inamide（Co（II）Cbi+）在共底物ATP的存在和不存在下与LmEutT的相互作用。我们的数据表明，LmEutT显示类似的底物特异性SeEutT，并可以结合Co（II）Cbl和Co（II）Cbi+时，与MgATP复合，虽然专门转换Co（II）Cbl的4C物种。值得注意的是，LmEutT是迄今为止在产生催化相关的4C Co（II）Cbl物质方面研究的最有效的ACAT，在添加仅超过1摩尔当量的共底物MgATP时实现>98%的5C→4C转化产率。单核细胞增生李斯特菌EutT腺苷转移酶的光谱研究：四配位Cob（II）丙氨酸中间体形成的证据。
The EutT enzyme from Listeria monocytogenes (LmEutT) is a member of the family of ATP:cobalt(I) corrinoid adenosyltransferase (ACAT) enzymes that catalyze the biosynthesis of adenosylcobalamin (AdoCbl) from exogenous Co(II)rrinoids and ATP. Apart from EutT-type ACATs, two evolutionary unrelated types of ACATs have been identified, termed PduO and CobA. Although the three types of ACATs are non-homologous, they all generate a four-coordinate cob(II)alamin (4C Co(II)Cbl) species to facilitate the formation of a supernucleophilic Co(I)Cbl intermediate capable of attacking the 5’-carbon of co-substrate ATP. Previous spectroscopic studies of the EutT ACAT from Salmonella enterica (SeEutT) revealed that this enzyme requires a divalent metal cofactor for the conversion of 5C Co(II)Cbl to a 4C species. Interestingly, LmEutT does not require a divalent metal cofactor for catalytic activity, which exemplifies an interesting phylogenetic divergence amongst the EutT enzymes. To explore if this disparity in metal cofactor requirement amongst EutT enzymes correlates with differences in substrate specificity or the mechanism of Co(II)Cbl reduction, we employed various spectroscopic techniques to probe the interaction of Co(II)Cbl and cob(II)inamide (Co(II)Cbi+) with LmEutT in the absence and presence of co-substrate ATP. Our data indicate that LmEutT displays a similar substrate specificity as SeEutT and can bind both Co(II)Cbl and Co(II)Cbi+ when complexed with MgATP, though exclusively converts Co(II)Cbl to a 4C species. Notably, LmEutT is the most effective ACAT studied to date in generating the catalytically relevant 4C Co(II)Cbl species, achieving a >98% 5C→4C conversion yield on addition of just over one molar equivalent of co-substrate MgATP. Spectroscopic Study of the EutT Adenosyltransferase from Listeria monocytogenes: Evidence for the Formation of a Four-Coordinate Cob(II)alamin Intermediate.
登录
查看更多内容
影响因子：
3.2
作者：
Johnson, CLV;Pechonick, E;Bobik, TA
通讯作者：
Bobik, TA
影响因子：
15
作者：
Brooks, AJ;Vlasie, M;Brunold, TC
通讯作者：
Brunold, TC
影响因子：
2.9
作者：
Mera, Paola E.;St Maurice, Martin;Escalante-Semerena, Jorge C.
通讯作者：
Escalante-Semerena, Jorge C.
影响因子：
64.8
作者：
CHANG, GW;CHANG, JT
通讯作者：
CHANG, JT
影响因子：
3.2
作者：
Buan, NR;Suh, SJ;Escalante-Semerena, JC
通讯作者：
Escalante-Semerena, JC