Kinetic and Structural Analysis of Two Linkers in the Tautomerase Superfamily: Analysis and Implications.
Kinetic and Structural Analysis of Two Linkers in the Tautomerase Superfamily: Analysis and Implications.
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DOI：
10.1021/acs.biochem.1c00220
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发表时间：
2021-06-08
期刊：
影响因子：
2.9
通讯作者：
Whitman CP
中科院分区：
文献类型：
--
作者：
Baas BJ;Medellin BP;LeVieux JA;Erwin K;Lancaster EB;Johnson WH Jr;Kaoud TS;Moreno RY;de Ruijter M;Babbitt PC;Zhang YJ;Whitman CP
互变酶超家族（TSF）是一组酶和蛋白质的集合，它们共享一个简单的β结构支架。大多数成员由单个核心β - α - β基序或两个连续融合的β - α - β基序构成，其中n端脯氨酸（Pro-1）作为催化残基起着关键而不寻常的作用。累积的证据表明，基因融合事件发生在TSF的进化过程中，随后发生了复制（新融合的基因），导致了今天所见的活动多样化。对TSF序列相似网络（SSN）的分析发现了几个连接蛋白（“连接子”），它们的相似性连接了这些当代蛋白的亚群，这些亚群可能为结构-功能关系的变化提供线索，伴随着新活性的出现。在SSN中发现了先前未被鉴定的一对连接体（指定为N1和N2），它们连接了4-草草酸互变酶（4-OT）和顺-3-氯丙烯酸脱卤酶（顺- caad）亚群。顺式caad亚群中的N1具有完整的顺式caad活性位点残基，而4-OT亚群中的N2缺乏典型4-OT活性的关键精氨酸（Arg-39）。动力学表征和核磁共振分析表明，N1对顺式caad亚群的其他表征成员具有不同程度的活性。N2是一个温和的4-OT，但在丙烯和乙炔化合物的作用下表现出增强的水合酶活性，这可能是由于Arg-8和Arg-11的存在。晶体学分析为这些观察提供了结构背景。
The tautomerase superfamily (TSF) is a collection of enzymes and proteins that share a simple β structural scaffold. Most members are constructed from a single core β−α−β motif or two consecutively fused β−α−β motifs where the N-terminal proline (Pro-1) plays a key and unusual role as a catalytic residue. The cumulative evidence suggests that a gene fusion event took place in the evolution of the TSF followed by duplication (of the newly fused gene) to result in the diversification of activity that is seen today. Analysis of the sequence similarity network (SSN) for the TSF identified several linking proteins (“linkers”) whose similarity links subgroups of these contemporary proteins that might hold clues about structure-function relationship changes accompanying the emergence of new activities. A previously uncharacterized pair of linkers (designated N1 and N2) was identified in the SSN that connected the 4-oxalocrotonate tautomerase (4-OT) and cis-3-chloroacrylic acid dehalogenase (cis-CaaD) subgroups. N1, in the cis-CaaD subgroup, has the full complement of active site residues for cis-CaaD activity, whereas N2, in the 4-OT subgroup, lacks a key arginine (Arg-39) for canonical 4-OT activity. Kinetic characterization and NMR analysis show that N1 has activities observed for other characterized members of the cis-CaaD subgroup with varying degrees of efficiencies. N2 is a modest 4-OT, but shows enhanced hydratase activity using allene and acetylene compounds, which might be due to the presence of Arg-8 along with Arg-11. Crystallographic analysis provides a structural context for these observations.
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DOI：
10.1074/jbc.m117.815340
发表时间：
2018-02-16
期刊：
The Journal of biological chemistry
影响因子：
--
作者：
Davidson R;Baas BJ;Akiva E;Holliday GL;Polacco BJ;LeVieux JA;Pullara CR;Zhang YJ;Whitman CP;Babbitt PC
通讯作者：
Babbitt PC
影响因子：
2.9
作者：
Burks, Elizabeth A.;Fleming, Christopher D.;Mesecar, Andrew D.;Whitman, Christian P.;Pegan, Scott D.
通讯作者：
Pegan, Scott D.
影响因子：
2.9
作者：
Poelarends, GJ;Serrano, H;Whitman, CP
通讯作者：
Whitman, CP
影响因子：
2.9
作者：
Poelarends, Gerrit J.;Almrud, Jeffrey J.;Whitman, Christian P.
通讯作者：
Whitman, Christian P.
影响因子：
2.9
作者：
Taylor, AB;Czerwinski, RM;Hackert, ML
通讯作者：
Hackert, ML