Roles of conserved residues in the arginase family
Roles of conserved residues in the arginase family
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DOI：
10.1016/s0167-4838(97)00131-3
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发表时间：
1998-01-15
期刊：
影响因子：
--
通讯作者：
Morris, SM
中科院分区：
文献类型：
--
作者：
Perozich, J;Hempel, J;Morris, SM
精氨酸酶和相关酶将精氨酸或类似的含氮化合物代谢为区域或甲酰胺。在本报告中，生成了该家族 31 名成员的序列比对。该比对与大鼠肝精氨酸酶的晶体结构一起，允许将可能的功能或结构作用分配给 32 个保守残基和保守取代。之前通过分析 I 型精氨酸酶基因的遗传缺陷，将其中两个残基鉴定为功能必需的残基。近一半的保守残基是位于蛋白质结构关键弯曲处的甘氨酸或脯氨酸。大多数金属配位残基，包括一个组氨酸和四个天冬氨酸残基，都是严格保守的。参与金属结合和催化的另外两个组氨酸在所有精氨酸酶和几乎所有其他家族成员中都是保守的。具有不变相似性的两个位置可以充当间接金属配体。还提出了这个家族内部的进化关系。脊椎动物 I 型和 II 型精氨酸酶似乎是独立于早期基因复制事件而发展的。来自秀丽隐杆线虫的尿素水解酶序列与其他精氨酸酶的相关性比之前认识的更为密切，而来自詹氏甲烷球菌和甲烷嗜热菌的未分类酶似乎与精氨酸酶相关酶更相似。此外，来自拟南芥和集胞藻的酶（之前被鉴定为精氨酸酶）比目前已知的精氨酸酶更类似于精氨酸酶相关酶。 (C) 1998 Elsevier Science B.V.
Arginases and related enzymes metabolize arginine or similar nitrogen-containing compounds to area or formamide. In the present report a sequence alignment of 31 members of this family was generated. The alignment, together with the crystal structure of rat liver arginase, allowed the assignment of possible functional or structural roles to 32 conserved residues and conservative substitutions. Two of these residues were previously identified as functionally essential by analysis of inherited defects in the type I arginase gene. Nearly half of the conserved residues are either glycines or prolines located at critical bends in the protein structure. Most metal-coordinating residues, including one histidine and four aspartic acid residues, are strictly conserved. Two additional histidines involved in metal-binding and catalysis are conserved in all arginases and in almost all other family members. Two positions with invariant similarities may serve as indirect metal ligands. Evolutionary relationships within this family were also suggested. Vertebrate type I and II arginases appear to have developed independently from an early gene duplication event. A ureohydrolase sequence from Caenorhabditis elegans is more closely related to other arginases than previously appreciated, while unclassified enzymes from Methanococcus jannaschii and Methanothermus fervidus appear more similar to arginase-related enzymes. In addition, enzymes from Arabidopsis thaliana and Synechocystis, previously identified as arginases, more closely resemble arginase-related enzymes than currently known arginases. (C) 1998 Elsevier Science B.V.